Thermal and X-Ray Diffraction Studies of the NaNbO3[Single Bond]KNbO3 System

✍ Scribed by Tennery, Victor J.

• Book ID: 121185922
• Publisher: American Institute of Physics
• Year: 1968
• Tongue: English
• Weight: 694 KB
• Volume: 39
• Category: Article
• ISSN: 0021-8979
• DOI: 10.1063/1.1655833

✦ Synopsis

Thermal and x-ray diffraction measurements on compositions from the system Na"K1-zNbOa h~ve revealed the presence of phase boundaries at approximately 82.5, 67.5, and 52.5. mole X ~a~b03.at 25 C, in addition to one very near the NaNbOa end member. The optimum piezoele~tnc I?roperbes. In t;hls system are apparently associated with compositions near the latter boundary. Calonmetnc dete~natlOns of t~e enthalpy and entropy changes associated with the ferroelectric-->ferroeIectric and fe~roelec~nc-->paraelectnc transformations in the system clearly revealed the presence of the phase b~undanes ~hile measureme~ts of the transformation temperatures alone did not readily reveal the boundanes. Two different superlattice perovskite phases were observed in the system, one existing in the region. ",0.98~x~0.825 and another in the region 0.825~x~0.675. No multiple-cell structures were observed In the system at NaNbOa concentrations below about 70 mole%.