Department of Earth Sciences, University of Cambridge, Cambridge, UK.
J Phys Condens Matter. 2011 Jun 8;23(22):222202. doi: 10.1088/0953-8984/23/22/222202. Epub 2011 May 16.
Ferroelectric hysteresis measurements on ceramic lawsonite show a temperature dependence of the remanent polarization P(r) = P(o)Θ(s)(cothΘ(s)/T - cothΘ(s)/T(c)) ∼ Q(2), Θ(s) = 26 K, where Q is the thermodynamic order parameter of the phase transition Pmcn-P 2(1)cn. This almost linear temperature evolution of P(r) proves the improper nature of ferroelectricity in lawsonite. The Curie temperature is T(c) = 124 K. The phase transition is strictly continuous, with a weak conjugated field near the transition point, and hydrogen ordering is discussed as the primary driving mechanism.
对陶瓷蓝片岩的铁电滞后测量表明剩余极化强度 P(r) = P(o)Θ(s)(cothΘ(s)/T - cothΘ(s)/T(c)) ∼ Q(2)，Θ(s) = 26 K，其中 Q 是相变为 Pmcn-P 2(1)cn 的热力学序参量。P(r) 的这种几乎线性的温度演化证明了蓝片岩中铁电性的不当性质。居里温度为 T(c) = 124 K。相变是严格连续的，在相变点附近存在弱共轭场，并且讨论了氢键有序化作为主要的驱动机制。
