Li doping effect on properties and phase transfomations of KNbO3

✍ Scribed by V.A. Trepakov; M.E. Savinov; V Železný; P.P. Syrnikov; A. Deyneka; L. Jastrabik

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 257 KB
• Volume: 27
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2007.02.113

✦ Synopsis

Dielectric permittivity and infrared reflectivity spectra of Li doped KNbO 3 single crystals have been studied for the first time for K 1-x Li x NbO 3 with x = 0.015, 0.02, 0.065. It was found that Li admixture results in occurrence of dielectric relaxation with the relaxation parameters very close to those in Li doped KTaO 3 . The relaxation was attributed to /2 dipole reorientation of Li + 1 0 0 off-centers substituted for K + , which appear to be present in both paraelectric cubic phase and in ferroelectric phase down to low-temperatures. Besides, Li doping is accompanied by an increase of the cubic-tetragonal phase transition temperature, a decrease of tetragonal-orthorhombic-rhombohedral phase transition temperatures and TO soft mode stiffening at room temperature.