Crystal Growth and Mechanical Properties of Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 Single Crystal Produced by Solution Bridgman Method

• Published in: Japanese Journal of Applied Physics Vol. 38; no. 9S; p. 5512
• Main Authors: Hosono, Yasuharu, Harada, Kouichi, Shimanuki, Senji, Saitoh, Shiroh, Yamashita, Yohachi
• Format: Journal Article
• Language: English
• Published: 01.09.1999
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.38.5512

High-quality, 40-mm-diameter piezoelectric Pb[(Zn 1/3 Nb 2/3 ) 0.91 Ti 0.09 ]O 3 single crystals (PZNT91/9) were successfully grown by the solution Bridgman method. Vickers hardness and fracture toughness of a PZNT91/9 wafer cut from a crystal were investigated by a microindentation technique. The Vickers hardness of PZNT91/9 was 2.6 GPa (transparent area) and 2.2 GPa (opaque area). The Vickers hardness of the transparent area in PZNT91/9 was equivalent to that of PZT ceramic. The fracture toughness of the transparent area of PZNT91/9 was markedly different depending on the domain direction: K IC =0.80 MPa·m 1/2 (vertical to the domain wall); and K IC =0.38 MPa·m 1/2 (parallel to the domain wall). Although the fracture toughness of PZNT91/9 is smaller than that of PZT ceramic, it is possible to cut the crystals for fine-pitch dicing, as required to produce array-type medical transducers, without serious problems.