Effect of Hydrostatic Pressure on the Low-Temperature Phase Transitions in<b><i>N</i>(<i>C</i><i>H</i><sub>3</sub>)<sub>4</sub><i><i>X</i></i><i>B</i><i>r</i><sub>3</sub></b>(<i>X</i>: Mn, Ni, Cd)
作者:Kazuo Gesi
DOI:10.1143/jpsj.65.1297
日期:1996.5.15
The effect of hydrostatic pressure on the low-temperature structural phase transitions in N(CH3)(4)XBr(3) (X: Mn, Ni, Cd) has been studied. The I-II transition temperatures of N(CH3)(4)MnBr3 (140 K at atmospheric pressure), N(CH3)(4)NiBr3 (135 K), and N(CH3)(4)CdBr3 (161 K; the ferroelectric Curie temperature) increase linearly with increasing pressure with coefficients of 0.075K K/MPa, 0.092 K/MPa, and 0.086 K/MPa, respectively. As pressure increases the II-III transition temperature of N(CH3)(4)NiBr3 (97 K) decreases with a pressure coefficients of -0.07 K/MPa. The results are compared with those previously reported for N(CH3)(4)XCl(3)-type crystals (X: Mn,Cd) and discussed.