Preparation and characterization of transparent magneto‐optical Ho2O3 ceramics

• Published in: Journal of the American Ceramic Society Vol. 102; no. 1; pp. 118 - 122
• Main Authors: Lu, Bin, Cheng, Hongmei, Xu, Xinxin, Chen, Hongbing
• Format: Journal Article
• Language: English
• Published: Columbus Wiley Subscription Services, Inc 01.01.2019
• Subjects: Ceramics; holmium oxide; layered rare‐earth hydroxide; magneto‐optical ceramics; Morphology; precipitation; Pyrolysis; Roasting; Single crystals; Sintering (powder metallurgy); Transmittance; transparent ceramics
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.16096

Transparent magneto‐optical Ho2O3 ceramics were successfully prepared with an in‐line transmittance of ~73% at the wavelength of 1000 nm (~90% of the theoretical transmittance of Ho2O3 single crystal) and an average grain size of ~28 μm. The ceramics were fabricated using sulfate‐exchanged nitrate‐type layered rare‐earth hydroxide as the precipitation precursor at a relatively low sintering temperature of 1700°C. The layered compound exhibited nanosheet morphology and fully collapsed into a round oxide powder with an average particle size of ~48 nm by pyrolysis. Calcination temperature for Ho2O3 powder significantly affected the optical quality of the sintered body and the optimum calcination temperature was found to be 1050°C. The transparent magneto‐optical Ho2O3 ceramics displayed wavelength‐dependent Verdet constants of −180, −46, and −20 rad/Tm at 632, 1064, and 1550 nm, respectively. Thus, the Ho2O3 ceramics show good potential for applications in high‐power laser systems.