Transparent complex oxide sintered body, manufacturing method thereof, and magneto-optical device

Patent metadata

Field	Value
Publication number	US-11208733-B2
Application number	US-201916288608-A
Country	US
Kind code	B2
Filing date	Feb 28, 2019
Priority date	Mar 9, 2018
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A transparent complex oxide sintered body is manufactured by sintering a compact in an inert atmosphere or vacuum, and HIP treating the sintered compact, provided that the compact is molded from a source powder based on a rare earth oxide: (TbxY1-x)2O3 wherein 0.4≤x≤0.6, and the compact, when heated in air from room temperature at a heating rate of 15° C./min, exhibits a weight gain of at least y % due to oxidative reaction, y being determined by the formula: y=2x+0.3. The sintered body has a long luminescent lifetime as a result of controlling the valence of Tb ion.

First claim

The invention claimed is:

1. A method for manufacturing a transparent complex oxide sintered body comprising the steps of:
providing a source powder comprising a rare earth oxide represented by the compositional formula: (Tb x Y 1-x ) 2 O 3 wherein x is a number from 0.4 to 0.6, and a sintering aid comprising an oxide of at least one element selected from Group 2 elements and Group 4 elements, the source powder being prepared by:
furnishing an aqueous solution containing (a) terbium ions, (b) yttrium ions, and (c) ions of at least one element of the sintering aid, letting components (a), (b) and (c) co-precipitate from the solution, filtering and oxidizing the co-precipitate, and
heat treating the oxidized co-precipitate or an oxide thereof by heating in an oxygen-containing atmosphere at a temperature of from 800° C. to less than 1,200° C. and then cooling in an inert atmosphere, vacuum or reducing atmosphere down to 350° C. or below, and
molding a compact from the source powder;

wherein a powder sample taken from the compact or a compact prepared under the same condition as the compact, when heated in air from room temperature at a heating rate of 15° C./min, exhibits a weight gain of at least y % due to oxidative reaction starting from a temperature of at least 250° C., y being determined by the formula (I):
y= 2 x+ 0.3  (I), and

wherein x is the number from 0.4 to 0.6,

sintering the molded compact in an inert atmosphere or vacuum;
hot isostatic pressing (HIP) the sintered compact to form a transparent complex oxide sintered body,
wherein when excited with excitation light of wavelength 380 nm, the transparent complex oxide sintered bod emits light including a component of wavelength 545 nm which has a luminescent lifetime of at least 0.3 ms, and a specimen of 11 mm long made from the sintered body has an overall light transmittance of at least 81.0% at a wavelength of 1,064 nm.

2. The method of claim 1 , further comprising, after the molding step, subjecting the molded compact to binder burnout at a temperature of up to 350° C.

3. The method of claim 2 , further comprising, after the burnout step, subjecting the compact to reducing treatment in a reducing atmosphere at a temperature of 100° C. to 350° C.

4. The method according to claim 1 , wherein in the heat treating step, the oxygen-containing atmosphere is an atmosphere containing at least 20 vol % oxygen.

5. The method according to claim 1 , wherein in the heat treating step, the oxidized co-precipitate or the oxide thereof is heated at a temperature of from 900° C. to 1,150° C.

6. The method according to claim 2 , wherein the binder burnout is performed at a temperature of up to 300° C.

7. The method according to claim 1 , wherein the sintering aid is included at from 1 part to 3 parts by weight per 100 parts by weight of the rare earth oxide.

8. The method according to claim 1 , wherein the sintering aid is selected from the group consisting of zirconium oxide and hafnium oxide.

9. The method according to claim 1 , wherein in the sintering step, the molded compact is sintered at a temperature of 1,400 to 1,600° C.

10. A transparent complex oxide sintered body obtained by the method according to claim 1 ,
wherein the transparent complex oxide sintered body comprises a rare earth oxide represented by the compositional formula: (Tb x Y 1-x ) 2 O 3 ,
wherein x is a number from 0.4 to 0.6,
wherein when excited with excitation light of wavelength 380 nm, the transparent complex oxide sintered body emits light including a component of wavelength 545 nm which has a luminescent lifetime of at least 0.3 ms, and a specimen of 11 mm long made from the sintered body has an overall light transmittance of at least 81.0% at a wavelength of 1,064 nm.

11. The transparent complex oxide sintered body according to claim 10 , wherein x is a number from 0.4 to 0.5.

12. The transparent complex oxide sintered body according to claim 10 , wherein the overall light transmittance at a wavelength of 1,064 nm is at least 81.2%.

13. A magneto-optical device comprising a Faraday rotator using the transparent complex oxide sintered body of claim 10 .

Assignees

• Shinetsu Chemical Co

Inventors

• Aoki Shinji
• Tanaka Keita

Classifications

• C04B2235/3215

  Barium oxides or oxide-forming salts thereof · CPC title

• C04B2235/662

  Annealing after sintering · CPC title

• C04B2235/762

  Cubic symmetry, e.g. beta-SiC · CPC title

• C04B2235/3852

  Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title