Phase transition and dielectric properties for perovskite-type oxyfluorides, (1-x)KNbO3-xKMgF3

2016 Fiscal Year Final Research Report

• Project/Area Number: 26410078
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic chemistry
• Research Institution: Tokai University
• Principal Investigator: Katsumata Tetsuhiro 東海大学, 理学部, 教授 (90333020)
• Research Collaborator: INAGUMA Yoshiyuki 学習院大学, 理学部, 教授 ; MORI Daisuke 学習院大学, 理学部, 助教 ; MIYMOTO Yasuo 東海大学, 技術共同管理室, 室長 ; HARAKI Takeshi ; KURAYA Ryosyke ; SAWADA Nobuhiro ; MIWA Hidehiro
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 酸フッ化物 / ペロフスカイト / 強誘電体 / 構造相転移 / リラクサー

Outline of Final Research Achievements

(1-x)KNbO3-xKMgF3 was synthesized using a sealed silica tube with an oxygen generator (KNMOF-O2) and high-pressure and high-temperature apparatus (KNMOF-hp) and the variations of the crystal structure with phase transition and the dielectric properties were investigated. By high- and low-temperature X-ray diffraction, it was found that the phase transition temperatures varies with increasing x and structural change with the phase transitions were ambiguous and dispersive in wide temperature range. However, the phase transition temperatures were almost constant for x=0.05 and did not merged. In the temperature dependence of the dielectric permittivity, the broad maximum was observed in the vicinity of 400 K for x=0.05 (KNMOF-hp) and its value reached an approximately 2200, which is higher than that of the orthorhombic phase of KNbO3 dense ceramics.

Free Research Field

無機固体化学