1. FeSe_1-xTe_xThe preparation process of the target material is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: proportioning and weighing the raw materials: the iron powder is 100 meshes, the selenium powder is 200 meshes, and the tellurium powder is 100 meshes;

step two: placing the weighed powder in an agate mortar for fully grinding for 30min, then keeping the ground mixed powder at the pressure of 400Mpa for 10min, pressing into tablets, packaging in a vacuum quartz tube, and carrying out a first solid-phase reaction;

step three: raising the temperature to 400 ℃ at the heating rate of 5 ℃/min, pre-reacting for 24 hours, raising the temperature to 700 ℃ at the heating rate of 5 ℃/min, preserving the temperature for 3 days, and then reducing the temperature to room temperature;

step four: crushing the flaky mixed powder, grinding for 60min, keeping the pressure of 400Mpa for 10min, pressing into a tablet, packaging in a vacuum quartz tube, and carrying out a second solid phase reaction;

step five: heating to 700 deg.C at a rate of 2 deg.C/min, maintaining for 3 days, and cooling to room temperature;

step six: crushing the flaky mixed powder, grinding for 60min, keeping the pressure of 400Mpa for 10min, pressing into a tablet, packaging in a vacuum quartz tube, and carrying out a third solid phase reaction;

step seven: heating to 700 deg.C at a rate of 2 deg.C/min, maintaining for 3 days, and cooling to room temperature;

step eight: crushing the flaky mixed powder for 60min, prepressing the powder blank sintered for three times into a target, wrapping the target with graphite paper, and placing the target in a graphite mold with the diameter of 20 mm;

step nine: hot-pressing and sintering: pumping and washing the sintering furnace cavity with argon for three times, and keeping the vacuum degree at 10^-2Pa, applying 27MPa pressure to the powder blank in the die, keeping the pressure in the whole sintering process, heating to 400 ℃ with 30% output power for 30min, heating to the target temperature of 400-700 ℃ with 50% output power for 30min, and finally keeping the temperature at 400-700 ℃ for 12 hours;

step ten: finishing the target material: and sequentially polishing the surface of the target material by 1500-mesh, 2000-mesh and 2500-mesh abrasive paper, and finally polishing by using water-soluble diamond grinding paste with the model of DNW0.5 to obtain a smooth and flat target material surface.

2. FeSe according to claim 1_1-xTe_xThe preparation process of the target material is characterized by comprising the following steps: in the first step, the purity of the iron powder is 99.95%, and the purities of the selenium powder and the tellurium powder are both 99.99%.

3. FeSe according to claim 1_1-xTe_xThe preparation process of the target material is characterized by comprising the following steps: and the grinding process in the second, fourth, sixth and eighth steps is carried out in a glove box which is filled with argon for protection and has a water value of less than 0.1ppm and an oxygen value of less than 0.1 ppm.

Background

FeSe_1-xTe_xThe material has important application prospect in the design of the next generation high field magnet by virtue of high critical magnetic field, high critical current density and small anisotropy. The primary problem to be solved in winding high-field magnets is to prepare high-performance FeSe_1-xTe_xThe long strip is coated with a conductor. Pulsed Laser Deposition (PLD) is currently FeSe_1-xTe_xThe most prominent method of preparation of coated conductors. In FeSe_1-xTe_xIn the preparation of long-strip coated conductors, FeSe_1-xTe_xThe target material is a sputtering source which continuously generates plasma plume through bombardment of PLD laser. The FeSe is prepared by the traditional solid phase reaction method_1-xTe_xThe compactness of the target material is not high generally. The target material is easy to pulverize under the bombardment of high-energy density and high-frequency laser generated by PLD, so that subsequent film forming is not smooth and poor in uniformity, and the preparation of a long-belt coating conductor cannot be realized.

Disclosure of Invention

In order to overcome the problems, the invention provides FeSe with high quality and adjustable density_1-xTe_xA preparation process of a target material.

The technical scheme adopted by the invention is as follows:

FeSe_1-xTe_xThe preparation process of the target comprises the following steps:

the method comprises the following steps: proportioning and weighing the raw materials: the iron powder is 100 meshes, the selenium powder is 200 meshes, and the tellurium powder is 100 meshes;

step two: placing the weighed powder in an agate mortar for fully grinding for 30min, then keeping the ground mixed powder at the pressure of 400Mpa for 10min, pressing into tablets, packaging in a vacuum quartz tube, and carrying out a first solid-phase reaction;

step three: raising the temperature to 400 ℃ at the heating rate of 5 ℃/min, pre-reacting for 24 hours, raising the temperature to 700 ℃ at the heating rate of 5 ℃/min, preserving the temperature for 3 days, and then reducing the temperature to room temperature;

step four: crushing the flaky mixed powder, grinding for 60min, keeping the pressure of 400Mpa for 10min, pressing into a tablet, packaging in a vacuum quartz tube, and carrying out a second solid phase reaction;

step five: heating to 700 deg.C at a rate of 2 deg.C/min, maintaining for 3 days, and cooling to room temperature;

step six: crushing the flaky mixed powder, grinding for 60min, keeping the pressure of 400Mpa for 10min, pressing into a tablet, packaging in a vacuum quartz tube, and carrying out a third solid phase reaction;

step seven: the temperature was raised to 700 ℃ at a rate of 2 ℃/min, held for 3 days and then allowed to cool to room temperature. Ensuring the reaction of the powder blank to be sufficient;

step eight: crushing the flaky mixed powder for 60min, prepressing the powder blank sintered for three times into a target, wrapping the target with graphite paper, and placing the target in a graphite mold with the diameter of 20 mm;

step nine: hot-pressing and sintering: pumping and washing the sintering furnace cavity with argon for three times, and keeping the vacuum degree at 10^-2Pa, avoiding the influence on the quality of the final target due to the contact of the target with more oxygen, applying a pressure of 27MPa to a powder blank in a die, keeping the pressure in the whole sintering process, heating to 400 ℃ in 30min at 30% of output power, heating to a target temperature of 400-700 ℃ in 30min at 50% of output power, and finally preserving the temperature for 12 hours at 400-700 ℃, so that the interior of the prepressed target is densified, and the density of the finished target is improved.

Step ten: finishing the target material: and sequentially polishing the surface of the target material by 1500-mesh, 2000-mesh and 2500-mesh abrasive paper, and finally polishing by using water-soluble diamond grinding paste with the model of DNW0.5 to obtain a smooth and flat target material surface.

Wherein, in the first step, the purity of the iron powder is 99.95 percent, and the purities of the selenium powder and the tellurium powder are both 99.99 percent.

Wherein, the grinding process in the second, fourth, sixth and eighth steps is carried out in a glove box which is filled with argon for protection, has a water value less than 0.1ppm and an oxygen value less than 0.1ppm, so that the raw materials are ensured to be less contacted with oxygen, and the adverse effect on the finished target material is avoided.

The invention has the following advantages:

FeSe prepared by the technical process_1-xTe_xCompared with the target prepared by the prior art, the target has greatly improved compactness, and FeSe can be continuously regulated and controlled by changing the sintering target temperature_1-xTe_xCompactness of target and FeSe prepared at the same time_1-xTe_xThe phase of the target material is good; solves the problem of FeSe prepared by the prior process_1-xTe_xThe target material is not compact enough and is easy to be pulverized after being bombarded by pulse laser for many times; the preparation process is easy to realize industrialization and can be used for FeSe of hectometer and kilometer levels_1-xTe_xThe preparation of the long-strip coated conductor has good application prospect.

Drawings

FIG. 1 is a schematic diagram showing the variation of the density of a target material after sintering according to the solid-phase reaction method of the present invention along with the cold pressing pressure before sintering;

FIG. 2 is a schematic diagram showing the variation of the density of the target material after hot press sintering at a pressure of 27MPa according to the present invention with the sintering temperature;

fig. 3 is a schematic diagram of a large-size high-density FeSeTe target with a diameter of 60mm prepared according to the preparation process.

Detailed Description

The present invention will be further described below, but the present invention is not limited to these.

Examples

The invention provides FeSe_1-xTe_xThe preparation process of the target comprises the following steps:

proportioning and weighing the raw materials: the iron powder is 100 meshes, the purity is 99.95 percent, the selenium powder is 200 meshes, the purity is 99.99 percent, the tellurium powder is 100 meshes, and the purity is 99.99 percent; grinding the weighed powder in agate mortar for 30min, pressing the mixed powder into tablet at 400MPa for 10min, and packaging in vacuumCarrying out a first solid-phase reaction in a quartz tube; raising the temperature to 400 ℃ at the heating rate of 5 ℃/min, pre-reacting for 24 hours, raising the temperature to 700 ℃ at the heating rate of 5 ℃/min, preserving the temperature for 3 days, and then reducing the temperature to room temperature; crushing the flaky mixed powder, grinding for 60min, keeping the pressure of 400Mpa for 10min, pressing into a tablet, packaging in a vacuum quartz tube, and carrying out a second solid phase reaction; heating to 700 deg.C at a rate of 2 deg.C/min, maintaining for 3 days, and cooling to room temperature; crushing the flaky mixed powder, grinding for 60min, keeping the pressure of 400Mpa for 10min, pressing into a tablet, packaging in a vacuum quartz tube, and carrying out a third solid phase reaction; the temperature was raised to 700 ℃ at a rate of 2 ℃/min, held for 3 days and then allowed to cool to room temperature. Ensuring the reaction of the powder blank to be sufficient; crushing the flaky mixed powder for 60min, prepressing the powder blank sintered for three times into a target, wrapping the target with graphite paper, and placing the target in a graphite mold with the diameter of 20 mm; all grinding processes are carried out in a glove box which is filled with argon for protection, has a water value less than 0.1ppm and an oxygen value less than 0.1ppm, so that the raw materials are ensured to be less contacted with oxygen, and the adverse effect on the finished target material is avoided; hot-pressing and sintering: pumping and washing the sintering furnace cavity with argon for three times, and keeping the vacuum degree at 10^-2Pa, avoiding the influence on the quality of the final target due to the contact of the target with more oxygen, applying a pressure of 27MPa to a powder blank in a die, keeping the pressure in the whole sintering process, heating to 400 ℃ in 30min at 30% of output power, heating to 400-700 ℃ in 30min at 50% of output power, and finally keeping the temperature at 400-700 ℃ for 12 hours to densify the interior of the pre-pressed target and improve the density of the finished target; finishing the target material: and sequentially polishing the surface of the target material by 1500-mesh, 2000-mesh and 2500-mesh abrasive paper, and finally polishing by using water-soluble diamond grinding paste with the model of DNW0.5 to obtain a smooth and flat target material surface.

As shown in fig. 1, the density of the target material after sintering by the solid-phase reaction method is changed along with the cold pressing pressure before sintering;

as shown in fig. 2, the target density after hot-press sintering under a pressure of 27Mpa varies with the sintering temperature, and the circle represents the target density pre-pressed (cold-pressed) before hot-press, which shows that the target density after hot-press sintering is significantly increased;

as shown in fig. 3, the large-size high-density FeSeTe target material with a diameter of 60mm is prepared according to the preparation process.

It is noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.