PURPOSE: To highly vitrify PLZT and to improve its electro-optical characteristic by using a first crucible made of a material inert to PbO, placing the calcined product in a second crucible, and calcining the PLZT material in a specified manner.
CONSTITUTION: A two-stage holder 2 is placed on a seat 1a, a PLZT formed product 3 to be calcined is placed on each stage of the holder 2, and a turned- down inner crucible 4a is placed to cover the product 3 and so on. The assembly is then placed in an intermediate crucible 5a, an atmospheric material P is filled into the intermediate crucible 5a, and a lid 6a is put on. The intermediate crucible 5a is placed in an outer crucible 8 provide with a lid 7, an oxygen supply port 9 is furnished to the outer crucible 8, and oxygen is successively supplied from the supply port 9. The PLZT to be calcined by using the device has a composition wherein a part of the zirconium lead titanate is substituted for lanthanum. Pb(NO3)2, La(NO3)3.6H2O, ZrO(NO3)2.2H2O, and Ti(OBu)4 are mixed, for example, and the mixture is calcined and crushed to obtain PLZT raw powder.
DOI NOBUYUKI
INOUE HIROSHI
HAYASHI KUNIHIKO
OKAMOTO SUSUMU
MAEOKA TOSHIAKI
HAYASHI KAGAKU KOGYO KK