阅读说明：本技术 一种砷化镉的制备方法 (Preparation method of cadmium arsenide ) 是由 苏湛 李康 狄聚青 黄文星 于 2021-09-17 设计创作，主要内容包括：本发明提供了一种砷化镉的制备方法,包括以下步骤：A)在氮气流动气氛中,按照配比将镉料和砷料置于装料部件中,在所述装料部件中所述镉料置于所述砷料上部；B)将步骤A)得到的装料部件放置于反应仪器中,将所述反应仪器抽真空后充氮气至常压,重复若干次后充入氢气；C)将步骤B)得到的反应仪器置于加热炉的上方,将加热炉预热,再将反应仪器降至加热炉中加热,反应,最后将反应仪器升至炉外淬火,得到砷化镉。本申请提供的砷化镉的制备方法具有较高的反应效率和产品纯度,且具有较低的产品损耗。(The invention provides a preparation method of cadmium arsenide, which comprises the following steps: A) in a nitrogen flowing atmosphere, placing a cadmium material and an arsenic material into a charging part according to a ratio, wherein the cadmium material is placed on the upper part of the arsenic material in the charging part; B) placing the charging part obtained in the step A) in a reaction instrument, vacuumizing the reaction instrument, filling nitrogen to normal pressure, repeating the steps for a plurality of times, and filling hydrogen; C) placing the reaction instrument obtained in the step B) above a heating furnace, preheating the heating furnace, then lowering the reaction instrument into the heating furnace for heating, reacting, and finally lifting the reaction instrument out of the furnace for quenching to obtain the cadmium arsenide. The preparation method of cadmium arsenide provided by the application has the advantages of higher reaction efficiency, higher product purity and lower product loss.)

1. A preparation method of cadmium arsenide comprises the following steps:

A) in a nitrogen flowing atmosphere, placing a cadmium material and an arsenic material into a charging part according to a ratio, wherein the cadmium material is placed on the upper part of the arsenic material in the charging part;

B) placing the charging part obtained in the step A) in a reaction instrument, vacuumizing the reaction instrument, filling nitrogen to normal pressure, repeating the steps for a plurality of times, and filling hydrogen;

C) placing the reaction instrument obtained in the step B) above a heating furnace, preheating the heating furnace, lowering the reaction instrument into the heating furnace for heating, reacting, and finally raising the reaction instrument out of the furnace for quenching to obtain cadmium arsenide;

the reaction apparatus in step C) was carried out under a flowing atmosphere of hydrogen.

2. The method according to claim 1, wherein the mass of the arsenic material is [ cadmium material weight/2.25 + (50-60) ] g.

3. The method according to claim 1, wherein the reaction apparatus is a quartz tube, an open end of the quartz tube is equipped with a sealing flange, a nitrogen gas inlet, a suction port, and a tail gas port, and the quartz tube is placed on a crane of the heating furnace.

4. The preparation method according to claim 3, wherein step B) is specifically:

starting a vacuumizing function of the heating furnace, reducing the pressure in the quartz tube to be below 5Pa, filling nitrogen to the normal pressure, repeating for 3-4 times, and finally filling hydrogen to the positive pressure in the quartz tube and opening a tail gas valve of a tail gas port.

5. The method according to claim 4, wherein the flow rate of the hydrogen gas is 0.5 to 1.5L/min.

6. The preparation method of claim 4, wherein in the step C), a heat insulation plate is arranged between the reaction instrument and the heating furnace, the preheating temperature is 750-850 ℃, and the heat preservation time is 10-30 min.

7. The method of manufacturing according to claim 4, further comprising, after the quenching:

and (3) cooling the quartz tube to be within 100 ℃, closing hydrogen, opening nitrogen, purging nitrogen for 0.5h, and closing.

8. The method according to claim 4, wherein the reaction time is 10 to 20min when the temperature of the heating furnace is increased to 750 to 850 ℃.

9. The production method according to any one of claims 1 to 8, wherein the charging member is a graphite crucible, the cadmium material is 5N cadmium lumps, and the arsenic material is 5N arsenic particles of 1 to 10 mm.

Technical Field

The invention relates to the technical field of high-purity metal compound materials, in particular to a preparation method of cadmium arsenide.

Background

Cadmium arsenide has the chemical formula Cd₃As₂The crystal is gray black cubic crystal, has molecular weight of 487.04, melting point of 721 deg.C, relative density of 6.2115, is easily soluble in nitric acid, slightly soluble in hydrochloric acid, and insoluble in water and aqua regia. Cadmium arsenide can release AsH when meeting acid₃And can be burnt when meeting the oxidant. The energy band structure of cadmium arsenide has the linear dispersion relation of no energy gap and zero electron effective mass, and has new optical, electric and magnetic properties. Compared with the traditional semiconductor, the cadmium arsenide has strong spin coupling, quantum property and super-high performanceHigh mobility and wide spectrum absorption characteristics, thereby having great application prospect in the fields of spinning electron, quantum information, photoelectric detection and the like.

Currently, the methods for cadmium arsenide mainly include Molecular Beam Epitaxy (Molecular Beam Epitaxy), Flux thermal (Flux Method), and Chemical vapor Deposition (Chemical vapor Deposition Method). The methods all need long processes, the time is from one day to several days, the existing synthesis methods mostly need harsh experimental conditions, and the cadmium arsenide synthesis has many problems, such as complex and tedious operation processes, high price, difficult storage and strong toxicity of experimental raw materials. Therefore, the method has important significance for establishing a novel method for synthesizing cadmium arsenide, which is simple and convenient to operate, low in cost and capable of being produced in large quantities and the application fields of related materials.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation method of cadmium arsenide, and the preparation method of cadmium arsenide provided by the application is high in reaction efficiency, high in product purity and low in loss rate.

In view of the above, the present application provides a method for preparing cadmium arsenide, comprising the following steps:

A) in a nitrogen flowing atmosphere, placing a cadmium material and an arsenic material into a charging part according to a ratio, wherein the cadmium material is placed on the upper part of the arsenic material in the charging part;

B) placing the charging part obtained in the step A) in a reaction instrument, vacuumizing the reaction instrument, filling nitrogen to normal pressure, repeating the steps for a plurality of times, and filling hydrogen;

C) placing the reaction instrument obtained in the step B) above a heating furnace, preheating the heating furnace, lowering the reaction instrument into the heating furnace for heating, reacting, and finally raising the reaction instrument out of the furnace for quenching to obtain cadmium arsenide;

the reaction apparatus in step C) was carried out under a flowing atmosphere of hydrogen.

Preferably, the mass of the arsenic material is [ the weight of the cadmium material/2.25 + (50-60) ] g according to the formula.

Preferably, the reaction instrument is a quartz tube, the open end of the quartz tube is provided with a sealing flange, a nitrogen gas inlet, an extraction opening and a tail gas opening, and the quartz tube is arranged on the lifting frame of the heating furnace.

Preferably, step B) is specifically:

starting a vacuumizing function of the heating furnace, reducing the pressure in the quartz tube to be below 5Pa, filling nitrogen to the normal pressure, repeating for 3-4 times, and finally filling hydrogen to the positive pressure in the quartz tube and opening a tail gas valve of a tail gas port.

Preferably, the flow rate of the hydrogen is 0.5-1.5L/min.

Preferably, in the step C), a heat insulation plate is arranged between the reaction instrument and the heating furnace, the preheating temperature is 750-850 ℃, and the heat preservation time is 10-30 min.

Preferably, the quenching further comprises the following steps:

and (3) cooling the quartz tube to be within 100 ℃, closing hydrogen, opening nitrogen, purging nitrogen for 0.5h, and closing.

Preferably, the reaction time is 10-20 min when the temperature of the heating furnace is increased to 750-850 ℃.

Preferably, the material loading part is a graphite crucible, the cadmium material is 5N cadmium blocks, and the arsenic material is 5N arsenic particles with the particle size of 1-10 mm.

The application provides a preparation method of cadmium arsenide, which comprises the steps of firstly placing a cadmium material and an arsenic material in a loading part, wherein the arsenic material is placed on the lower cadmium material, so that the cadmium material can be fully contacted with the arsenic material after being melted, and the reaction efficiency is improved; in the reaction process, the flowing hydrogen atmosphere is adopted, so that the oxygen content of the cadmium arsenide product can be effectively reduced, and the product purity is improved; and finally, in the reaction process, the reaction instrument quickly ascends and descends to enter a heating furnace so as to ensure that the materials are subjected to shock heating synthesis and shock cooling crystallization, the reaction efficiency and the production efficiency are improved, and the loss rate of cadmium arsenide is reduced.

Drawings

FIG. 1 is a schematic diagram of an apparatus for preparing cadmium arsenide according to the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In view of the problems of complicated process, high price, long time and low product purity in the preparation process of cadmium arsenide in the prior art, the application provides the preparation method of cadmium arsenide, and the preparation method can improve the reaction efficiency and the product purity. Specifically, the embodiment of the invention discloses a preparation method of cadmium arsenide, which comprises the following steps:

A) in a nitrogen flowing atmosphere, placing a cadmium material and an arsenic material into a charging part according to a ratio, wherein the cadmium material is placed on the upper part of the arsenic material in the charging part;

B) placing the charging part obtained in the step A) in a reaction instrument, vacuumizing the reaction instrument, filling nitrogen to normal pressure, repeating the steps for a plurality of times, and filling hydrogen;

C) placing the reaction instrument obtained in the step B) above a heating furnace, preheating the heating furnace, lowering the reaction instrument into the heating furnace for heating, reacting, and finally raising the reaction instrument out of the furnace for quenching to obtain cadmium arsenide;

the reaction apparatus in step C) was carried out under a flowing atmosphere of hydrogen.

In the process of preparing cadmium arsenide, according to the detailed preparation process, the method specifically comprises the following steps: batching, charging, air pumping and inflating, heating, synthesizing and discharging; according to the invention, firstly, ingredients are prepared, cadmium blocks and arsenic particles can be selected as cadmium materials and arsenic materials respectively, the cadmium blocks are 5N cadmium blocks, and the arsenic particles are 5N arsenic particles with the size of 1-10 mm. In the present application, the arsenic material weight is ═ cadmium material weight/2.25 + (50-60) ] g; in a specific embodiment, the arsenic material weight is ═ cadmium material weight/2.25 +50] g; in the process, 50-60 g of arsenic particles are additionally supplemented, so that the loss of arsenic in the flowing atmosphere can be supplemented, and the overlarge deviation of the stoichiometric ratio of cadmium arsenide is avoided. The process was carried out in a glove box under a flowing nitrogen atmosphere.

After the materials are mixed, the materials are preferably charged in a graphite crucible, namely, arsenic materials are placed in the graphite crucible, the arsenic materials are paved at the bottom of the graphite crucible as much as possible, and cadmium materials are placed above arsenic blocks; the graphite crucible was then placed in a reaction apparatus, a quartz tube, and the process was also carried out in a glove box under a flowing nitrogen atmosphere.

According to the invention, after the material is loaded, the material is loaded into the furnace, the opening end of the quartz tube is provided with the sealing flange, the nitrogen gas inlet, the exhaust port and the tail gas port, the material is taken out from the glove box, and the assembled quartz tube is placed on the lifting frame of the heating furnace. After charging, in order to carry out the reaction, air pumping and charging operations are carried out so as to ensure that the oxygen content in the reaction atmosphere is reduced and the product purity is improved; the method specifically comprises the following steps: starting a vacuumizing function of the heating furnace, vacuumizing the pressure in the quartz tube to be below 5Pa, filling nitrogen to the normal pressure, repeating the step for three times, filling hydrogen to the positive pressure for the last time, opening a tail gas valve to enable the quartz tube to form a hydrogen flowing atmosphere, wherein the flow rate is 0.5-1.5L/min, and keeping until the quartz tube is discharged.

This application then preheats the quartz capsule, and it does not go on in the heating furnace, but places the quartz capsule in the top of heating furnace, specifically is: setting a heating procedure of the heating furnace to be 30-40 min for heating from room temperature to 750-850 ℃, and keeping the temperature for 10-30 min to stabilize the temperature; during the heating process, a heat insulation plate (shown in figure 1 in particular) must be arranged at the furnace mouth to prevent the temperature of the heater from losing and the cadmium arsenide from being synthesized in advance. After the heat preservation is finished, the heat insulation plate is taken down, the lifting frame of the heating furnace is quickly lowered, and the quartz tube is quickly lowered into the furnace body for heating. In the process, the temperature in the furnace body is firstly reduced, then is increased and then is reduced, and finally is returned to 750-850 ℃; after the quartz tube is completely lowered to the furnace body, the time is counted for 10-20 min when the temperature is raised to 750-850 ℃ (note that the temperature of the furnace body may exceed 750-850 ℃ due to the reaction heat release), and the time is counted by raising the temperature to 750-850 ℃. And after the timing is finished, starting the product furnace lifting frame to lift the quartz tube to the outside of the furnace body for quenching at room temperature, and after 5 minutes, putting back the heat insulation baffle to the furnace mouth. In the application, the materials in the quartz tube are synthesized and crystallized by sudden heating, so that the production efficiency and the product uniformity are improved. In the traditional slow heating synthesis method, cadmium arsenide with a higher melting point is partially synthesized in the heating process, so that the reaction is hindered, the raw material reaction is incomplete, and the mass loss of materials is large in a flowing atmosphere; the sudden heat synthesis adopted by the method quickly reaches the melting point of cadmium and the boiling point of arsenic, so that the reaction is more sufficient and thorough, and the time is saved. In addition, the loading mode of the cadmium under the arsenic realizes that arsenic particles are soaked in the molten cadmium during sudden heating, and is also beneficial to more sufficient synthesis reaction.

After the completion, discharging the product, namely closing hydrogen and opening nitrogen when the temperature of the quartz tube is reduced to 200 ℃, and closing the nitrogen purging over half an hour; taking the quartz tube and the flange down from the product furnace lifting frame, detaching the flange, and taking the graphite crucible out of the quartz tube; and (4) turning the graphite crucible upside down, knocking the bottom by a rubber hammer, knocking out the material, and carrying out vacuum packaging and storage.

According to the preparation method of cadmium arsenide, a hydrogen flowing atmosphere is adopted in the whole synthesis process, so that the contact between materials and oxygen is effectively avoided, the oxygen content of the product is reduced, and the purity is improved. The purity of the produced cadmium arsenide can reach 99.99%, and the risk of tube explosion caused by over-pressure in the arsenic-cadmium synthesis reaction is effectively reduced; meanwhile, in the synthesis process, the materials are subjected to shock heating synthesis and shock cooling crystallization, so that the production time is shortened, the production efficiency is improved, and in addition, the product segregation phenomenon is reduced and the product uniformity is improved due to shock cooling.

For further understanding of the present invention, the following examples are provided to illustrate the preparation method of cadmium arsenide provided by the present invention, and the scope of the present invention is not limited by the following examples.

Example 1

Preparing materials: selecting a piece of 5N cadmium in a glove box, weighing 2014.8g of the cadmium, and weighing 2014.8g/2.25+50g of 945.5g of 5N arsenic particles;

charging: firstly, placing 945.5g of weighed arsenic particles into a graphite crucible, paving the bottom of the graphite crucible, then placing a cadmium block into the graphite crucible, placing the cadmium block on the paved arsenic particles, and slowly placing the graphite crucible filled with materials into a quartz tube, wherein the process is also operated in a glove box;

charging: assembling the quartz tube, the gas path pipeline and the sealing flange, taking out the quartz tube and the gas path pipeline from the glove box, putting a product furnace lifting frame on the glove box, and closing a tail gas valve (the product furnace lifting frame only plays a role in lifting the quartz tube and is not shown in the figure 1);

air suction and inflation: starting a product furnace vacuumizing function, vacuumizing the pressure in the quartz tube to 3Pa, filling nitrogen to normal pressure, vacuumizing, filling nitrogen, vacuumizing and filling hydrogen, opening a tail gas valve after the hydrogen is filled to positive pressure to form hydrogen flowing atmosphere in the quartz tube, adjusting the flow rate to be 0.5L/min, and keeping the flow rate until discharging;

heating: placing a thermal insulation plate at a furnace mouth, setting and starting a product furnace to heat up from room temperature to 750 ℃ for 30min, and preserving heat for 10min to stabilize the temperature;

synthesizing: after the heat preservation is finished, the heat insulation plate is taken down, the product furnace lifting frame is quickly lowered, and the quartz tube is quickly lowered into the furnace body for heating; the temperature of the furnace body is reduced to 612.1 ℃ at the lowest, and then slowly rises; starting timing for 15min when the temperature rises to 750 ℃; after the timing is finished, starting a product furnace lifting frame to lift the quartz tube to the outside of the furnace body for room temperature quenching, simultaneously closing the heating, and after 5 minutes, putting back the heat insulation baffle to the furnace mouth;

discharging: and when the temperature of the quartz tube is reduced to 200 ℃, closing hydrogen, opening nitrogen, purging the nitrogen for half an hour, taking the quartz tube and the flange from the product furnace lifting frame, detaching the flange, taking the graphite crucible out of the quartz tube, inverting the graphite crucible, knocking the bottom by a rubber hammer, knocking out the material, and carrying out vacuum packaging and storage.

The whole process takes 3 hours, and the product has the cadmium content of 69.24 percent, the purity of 99.99 percent and the impurity content shown in the table 1 after sampling and analysis.

Example 2

Preparing materials: selecting a piece of 5N cadmium in a glove box, weighing 1995.8g of the cadmium, and weighing 1995.8g/2.25+50g of 937.0g of 5N arsenic particles;

charging: firstly, placing 937.0g of weighed arsenic particles into a graphite crucible, paving the bottom of the graphite crucible, then placing a cadmium block into the graphite crucible, and placing the cadmium block on the paved arsenic particles; slowly putting the graphite crucible filled with the materials into a quartz tube; this process also operates inside a glove box;

charging: assembling the quartz tube, the gas path pipeline and the sealing flange, taking out the quartz tube and the gas path pipeline from the glove box, putting a product furnace lifting frame on the glove box, and closing a tail gas valve (the product furnace lifting frame only plays a role in lifting the quartz tube and is not shown in the figure 1);

air suction and inflation: starting a product furnace vacuumizing function, vacuumizing the pressure in the quartz tube to 3Pa, filling nitrogen to normal pressure, vacuumizing, filling nitrogen, vacuumizing and filling hydrogen, opening a tail gas valve after the hydrogen is filled to positive pressure to form hydrogen flowing atmosphere in the quartz tube, adjusting the flow rate to be 0.5L/min, and keeping the flow rate until discharging;

heating: placing a thermal insulation plate at a furnace mouth, setting and starting a product furnace to heat up from room temperature to 750 ℃ for 30min, and preserving heat for 10min to stabilize the temperature;

synthesizing: after the heat preservation is finished, the heat insulation plate is taken down, the product furnace lifting frame is quickly lowered, the quartz tube is quickly lowered into the furnace body to be heated, the temperature of the furnace body is lowered to 618.9 ℃ at the lowest, then the temperature is slowly raised, and the timing is started for 15min when the temperature is raised back to 750 ℃; after the timing is finished, starting a product furnace lifting frame to lift the quartz tube to the outside of the furnace body for room temperature quenching, simultaneously closing the heating, and after 5 minutes, putting back the heat insulation baffle to the furnace mouth;

discharging: and when the temperature of the quartz tube is reduced to 200 ℃, closing hydrogen, opening nitrogen, purging the nitrogen for half an hour, taking the quartz tube and the flange from the product furnace lifting frame, detaching the flange, taking the graphite crucible out of the quartz tube, inverting the graphite crucible, knocking the bottom by a rubber hammer, knocking out the material, and carrying out vacuum packaging and storage.

The whole process takes 3 hours, and the product has the cadmium content of 69.23 percent, the purity of 99.99 percent and the impurity content shown in the table 1 after sampling analysis.

Comparative example 1

Preparing materials: selecting a piece of 5N cadmium in a glove box, weighing 1998.3g of the cadmium, and weighing 1998.3g/2.25+50g of 938.1g of 5N arsenic particles;

charging: firstly, placing 938.1g of weighed arsenic particles into a graphite crucible, paving the bottom of the graphite crucible, then placing a cadmium block into the graphite crucible, and placing the cadmium block on the paved arsenic particles; slowly putting the graphite crucible filled with the materials into a quartz tube; this process also operates inside a glove box;

charging: assembling the quartz tube, the gas path pipeline and the sealing flange, taking out the quartz tube and the gas path pipeline from the glove box, putting a product furnace lifting frame on the glove box, and closing a tail gas valve (the product furnace lifting frame only plays a role in lifting the quartz tube and is not shown in the figure 1);

air suction and inflation: starting a product furnace vacuumizing function, vacuumizing the pressure in the quartz tube to 2Pa, filling nitrogen to positive pressure, opening a tail gas valve after the nitrogen is filled to the positive pressure, forming a nitrogen flowing atmosphere in the quartz tube, adjusting the gas flow to be 0.5L/min, and keeping the gas flow until the quartz tube is discharged;

heating: placing a thermal insulation plate at a furnace mouth, setting and starting a product furnace to heat up from room temperature to 750 ℃ for 30min, and preserving heat for 10min to stabilize the temperature;

synthesizing: after the heat preservation is finished, the heat insulation plate is taken down, the product furnace lifting frame is quickly lowered, the quartz tube is quickly lowered into the furnace body to be heated, the temperature of the furnace body is lowered to 628.6 ℃ at the lowest, then the temperature is slowly raised, the timing is started for 15min when the temperature is raised to 750 ℃, the product furnace lifting frame is started after the timing is finished, the quartz tube is raised to the outside of the furnace body to be quenched at the room temperature, the heating is simultaneously closed, and the heat insulation baffle is put back to a furnace opening after 5 min;

discharging: when the temperature of the quartz tube is reduced to 200 ℃, closing hydrogen, opening nitrogen, purging the nitrogen for half an hour, taking the quartz tube and the flange from a product furnace lifting frame, disassembling the flange, taking the graphite crucible out of the quartz tube, turning the graphite crucible upside down, knocking the bottom by a rubber hammer, knocking out the materials, carrying out vacuum packaging and storing, taking 3 hours in the whole process, and carrying out sampling analysis, wherein the cadmium content of the product is 69.23 percent, the purity is 99.99 percent, and the impurity content is shown in the table 1 below.

Comparative example 2 (Slow temperature rise after descent)

Preparing materials: selecting a piece of 5N cadmium in a glove box, weighing 1987.6g of the cadmium, and weighing 1987.6g/2.25+50g of 933.4g of 5N arsenic particles;

charging: firstly, placing weighed 933.4 arsenic particles into a graphite crucible, paving the bottom of the graphite crucible, then placing a cadmium block into the graphite crucible, and placing the cadmium block on the paved arsenic particles; slowly putting the graphite crucible filled with the materials into a quartz tube; this process also operates inside a glove box;

charging: assembling a quartz tube, a gas circuit pipeline and a sealing flange, taking out the quartz tube and the gas circuit pipeline from the glove box, putting a product furnace lifting frame on the glove box, and closing a tail gas valve; the quartz tube was lowered into the furnace to the position shown in "as synthesized" in FIG. 1 (note: heating has not yet begun at this time);

air suction and inflation: starting a product furnace vacuumizing function, vacuumizing the pressure in a quartz tube to 2Pa, filling nitrogen to normal pressure, vacuumizing, filling nitrogen, vacuumizing and filling hydrogen; after the hydrogen is filled to positive pressure, opening a tail gas valve to form hydrogen flowing atmosphere in the quartz tube, adjusting the flow rate to be 0.5L/min, and keeping the flow rate until discharging;

heating and synthesizing: setting and starting a product furnace temperature rise program to rise from room temperature to 750 ℃ for 30min, and keeping the temperature for 15min to stabilize the temperature;

synthesizing: after the heat preservation is finished, starting a product furnace lifting frame to lift the quartz tube to the outside of the furnace body for room temperature quenching, simultaneously closing the heating, and after 5 minutes, putting back the heat insulation baffle to a furnace mouth;

discharging: and (3) when the temperature of the quartz tube is reduced to 200 ℃, closing hydrogen, opening nitrogen, purging the nitrogen for half an hour, taking the quartz tube and the flange from the product furnace lifting frame, detaching the flange, taking the graphite crucible out of the quartz tube, turning the graphite crucible upside down, knocking the bottom by a rubber hammer, knocking out the material, carrying out vacuum packaging and storing, and consuming 3 hours in the whole process.

The product performances of the examples and the comparative examples are tested, and the test results are shown in tables 1 and 2.

TABLE 1 data table of impurity contents of cadmium arsenide prepared in examples and comparative examples

TABLE 2 comparative data sheet for loss of material between examples and comparative examples

Experiment of	Cadmium/g	Arsenic/g	Total weight of raw materials/g	The obtained product/g	Loss per gram	Rate of loss/%)
							Example 1	2014.8	945.5	2960.3	2802.5	157.8	5.33％
Example 2	1995.8	937.0	2932.8	2787.3	145.5	4.96％
							Comparative example 1	1998.3	938.1	2936.4	2783.4	153.0	5.21％
Comparative example 2	1987.6	933.4	2921.0	2268.2	652.8	22.35％

According to the results, the data of the examples 1 and 2 and the comparative example 1 show that the hydrogen flowing atmosphere can be combined with oxygen to be discharged during the high-temperature synthesis of arsenic and cadmium, so that the oxygen content of the product is effectively reduced; comparative example 2 the product has serious quality loss, is loose and porous and does not meet the product requirements completely; therefore, the sudden thermal synthesis is a key factor for success and failure of the scheme for preparing cadmium arsenide.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.