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CN-121976105-A - Ce-based alloy sputtering target and preparation method thereof

CN121976105ACN 121976105 ACN121976105 ACN 121976105ACN-121976105-A

Abstract

The invention discloses a Ce-based alloy sputtering target and a preparation method thereof, wherein the sputtering target comprises any one of Sm, gd and Y, ce and unavoidable impurities, the content range of Sm, gd or Y elements is 5-25 atomic percent, the impurities comprise C, S and O, and the Vickers hardness of the sputtering target is more than 35 Hv. The Ce-based alloy sputtering target provided by the invention solves the problems that the existing Ce-based alloy target is easy to oxidize in the sputtering process, the sputtering rate is unstable, the formed CeO 2 -based electrolyte film is not compact, and the like.

Inventors

  • WU DAOGAO
  • ZHANG XIAOWEI
  • GUO XINYU
  • ZHONG JIAMIN
  • YU CHUANG
  • YANG HONGBO
  • YANG BINGZHENG
  • DONG RUIFENG
  • WANG ZHIQIANG
  • YANG FAN
  • LI SHUAN
  • XU MINGLEI
  • YANG WENCHENG

Assignees

  • 有研稀土新材料股份有限公司
  • 有研稀土高技术有限公司

Dates

Publication Date
20260505
Application Date
20251212

Claims (13)

  1. 1. The Ce-based alloy sputtering target is characterized by comprising any one of Sm, gd and Y, ce and unavoidable impurities, wherein the content range of Sm, gd or Y elements is 5-25 atomic percent, the impurities comprise C, S and O, and the Vickers hardness of the sputtering target is more than 35 Hv.
  2. 2. The Ce-based alloy sputtering target according to claim 1, wherein the C content is 80 wt. ppm or less and the fluctuation range of the C content is not more than 20%.
  3. 3. The Ce-based alloy sputtering target according to claim 1, wherein the S content is 100 ppm by weight or less and the fluctuation range of the S content is not more than 20%.
  4. 4. The Ce-based alloy sputtering target according to claim 1, wherein the O content is equal to or less than 1000 ppm by weight and the fluctuation range of the O content is not more than 20%.
  5. 5. The Ce-based alloy sputtering target according to claim 1,2,3 or 4, wherein the sputtering target further comprises at least one of Nb, al element, and the content of Nb or Al element is 50 to 400 ppm by weight.
  6. 6. The Ce-based alloy sputtering target according to claim 5, wherein the vickers hardness fluctuation range is controlled within 10%.
  7. 7. The Ce-based alloy sputtering target according to claim 1,2, 3, 4 or 6, wherein the sputtering surface of the sputtering target has a recrystallized structure, and the surface roughness Ra of the sputtering surface is not more than 3.2 μm.
  8. 8. The Ce-based alloy sputtering target according to claim 7, wherein the recrystallized structure has an average grain size of 100 μm or less and a maximum grain size of 150 μm or less.
  9. 9. The Ce-based alloy sputtering target according to claim 8, wherein in the recrystallized structure, the {100} crystal plane accounts for 40% to 60%, the {110} crystal plane accounts for 20% to 30%, and the total of the {100} crystal plane and the {110} crystal plane accounts for not less than 65%.
  10. 10. The Ce-based alloy sputtering target according to claim 9, wherein the number of carbon-oxygen-containing sulfide particles having a width of 10 μm or more in the direction of the largest dimension of the sputtering surface is < 50/mm 2 .
  11. 11. A method of producing a Ce-based alloy sputtering target according to any one of claims 1 to 10, comprising the steps of: S1, purifying metal Ce by a hydrogen plasma zone melting method to obtain a first purified product, and simultaneously purifying any one of metals Gd, sm and Y to obtain a second purified product, wherein the zone melting rate is controlled to be 5-30 mm/min, the zone melting times are more than or equal to 10 times, and the flow ratio of gas H 2 /Ar is 0.5-1:1; S2, heating and smelting the first purified material and the second purified material into melt by adopting a vacuum smelting mode, adding 0.1-0.5% by weight of refining agent for refining and degassing, and casting to obtain an ingot, wherein the refining agent comprises high-purity metal Mg or Ca; And S3, forging and annealing the cast ingot to obtain the Ce-based alloy sputtering target, wherein the forging step number is more than or equal to 2.
  12. 12. The method for preparing a Ce-based alloy sputtering target according to claim 11, wherein the step S3 comprises the steps of performing forging at room temperature in the first step, controlling the forging reduction ratio to be 10% -20% in the first step, and performing the forging under vacuum or inert protection conditions, controlling the forging temperature to be 200% -400 ℃ in the second step and the subsequent forging processes, controlling the single forging reduction ratio to be 20% -40%, and obtaining the Ce-based alloy sputtering target, wherein the average strain rate of the forging is 0.001-0.1S -1 , performing the forging along X, Y, Z directions, performing annealing treatment after each forging, controlling the annealing temperature to be 200% -350 ℃ and the annealing time to be 5-20 min.
  13. 13. The method of producing a Ce-based alloy sputtering target according to claim 11 or 12, wherein said S2 step further comprises adding at least one of Nb and Al to the mixture of said first purified product and said second purified product, and heating and melting the mixture into a melt.

Description

Ce-based alloy sputtering target and preparation method thereof Technical Field The invention belongs to the technical field of Ce-based alloy sputtering targets, and particularly relates to a Ce-based alloy sputtering target and a preparation method thereof. Background Solid Oxide Fuel Cells (SOFC) are the third generation fuel cells with the highest energy density, and have the characteristics of cleanliness, high efficiency, flexible fuel and the like, and the electrolyte in all-solid-state devices is the most central component. The conventional Y 2O3 stable ZrO 2 (YSZ) electrolyte material needs to work in the range of 800-1000 ℃, and the high-temperature operation condition can cause the problems of accelerated aging of components of the battery, shortened service life, limited selection of packaging materials and the like. Therefore, developing electrolyte materials at low and medium temperatures is one of the important development directions of SOFCs. CeO 2 as a ceramic material with fluorite properties, the conductivity of the electrolyte is significantly increased by 1 to 2 orders of magnitude relative to YSZ under the same temperature conditions, but this further results in a corresponding decrease in the conductivity of oxygen ions due to the relatively low concentration of oxygen vacancies within the crystal lattice. In order to relieve the problems of short circuit, poor stability and the like in a battery caused by valence change of Ce element in a reducing atmosphere and further improve the ion conductivity of CeO 2 -based electrolyte, research shows that the resistance is reduced by doping rare earth oxides such as Gd, sm, Y and the like in a CeO 2 film, so that the conductivity is improved. When the concentration of the doped ions is about 5% -25% (mole fraction), the oxygen ion conductivity value reaches the maximum value. The Ce-based alloy is used as a target, and the magnetron sputtering process is adopted to prepare the cerium oxide-based isolation layer on the surface of the electrolyte layer of the half cell of the solid oxide fuel cell, so that the preparation method has the advantages of compactness, simple device, easiness in large-scale stable preparation and the like, and becomes one of the common methods for the industrial production of the electrolyte film. However, metal Ce is active in nature, easy to oxidize in air, easy to corrode in a humid environment, meanwhile cerium can react with most metals and nonmetal at high temperature, a large number of carbon-oxygen-sulfur-containing compound inclusion particles are formed on a Ce-based sputtering surface, and the Ce-based alloy target is easy to introduce oxygen impurities to oxidize in the process of placing or sputtering in an oxygen atmosphere to cause unstable sputtering process due to the fact that the internal defects are large, coarse and uneven in grain size of the Ce-based target, uneven and non-compact in sputtering deposition rate and poor in film thickness uniformity, so that popularization and application of the metal Ce-based alloy target are severely limited. Disclosure of Invention Object of the invention The invention aims to provide a Ce-based alloy sputtering target and a preparation method thereof, and the Ce-based alloy sputtering target solves the problems that the existing Ce-based alloy target is easy to oxidize in the sputtering process, the sputtering rate is unstable, the formed CeO 2 -based electrolyte film is not compact and the like. (II) technical scheme In order to solve the above problems, a first aspect of the present invention provides a Ce-based alloy sputtering target, which includes any one of Sm, gd and Y, ce and unavoidable impurities, and has a low defect bonding energy and a low film stress due to the close radii of Gd 3+、Sm3+、Y3+ and Ce 4+, and is easy to form a defect-free film layer during the production process. In the design, if the doping amount is less than 5 atomic percent, the quantity of oxygen vacancies generated by cerium oxide is too small, the channel for oxygen ion migration is insufficient, the ion conductivity is difficult to meet the use requirement of devices such as fuel cells and the like, and the high-efficiency energy conversion requirement in medium and low temperature environments cannot be met, but if the doping amount exceeds 25 atomic percent, too much Sm or Gd or Y ions not only can aggravate the lattice distortion of the cerium oxide film, but also can cause repulsive interaction among the oxygen vacancies, and part of oxygen vacancies can be captured by Sm or Gd or Y ions to lose migration activity, so that the ion conductivity is reduced. Meanwhile, excessive doping can generate more material defects, so that the stability of the whole structure is damaged, for example, the material is easy to interdiffuse with other components during cofiring, and the whole performance of the device is further influenced. The impurity comprises C, S and O, the C conten