Wei Lai, Zhang Li-Li, Huang Yi-Neng
Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters, College of Physical Science and Technology, Yili Normal University, Yining, China.
National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, China.
Sci Rep. 2024 Nov 22;14(1):28924. doi: 10.1038/s41598-024-80454-7.
For relaxor-ferroelectrics and relaxor-ferromagnets, the initial Ehrenfest-classification gives no phase-transition that contradicts the measured order-parameter, while the classification according to order-parameter and its derivatives raises the question about the relationships between the phase-transition and the specific-heat peak above and near the transition temperature. Here, based on the free-energy (F) of the thermodynamic limit systems when the external-field (h) tends 0, thermal equilibrium phase-transitions of thermodynamic limit systems with temperature (T) are reclassified into: (1) Discontinuous phase-transition. [Formula: see text] and [Formula: see text] have discontinuities in a T range; (2) Continuous phase-transition. [Formula: see text] and [Formula: see text] are continuous with T, while [Formula: see text] and [Formula: see text] have discontinuities at a T point; and (3) Diffuse phase-transition. [Formula: see text] and [Formula: see text] are continuous with T, while they are respectively equal to 0 at the transition-temperature (T) and diffuse-temperature (T). The diffuse-region of the phase-transition is [Formula: see text] and the diffuse-degree [Formula: see text], naturally giving the relation of the phase-transition to the specific-heat peak.
对于弛豫铁电体和弛豫铁磁体，最初的埃伦费斯特分类法并未给出与测量的序参量相矛盾的相变，而根据序参量及其导数进行的分类则引发了关于相变与转变温度以上及附近的比热峰之间关系的问题。在此，基于外场（h）趋于0时热力学极限系统的自由能（F），将具有温度（T）的热力学极限系统的热平衡相变重新分类为：（1）不连续相变。[公式：见原文]和[公式：见原文]在一个T范围内存在不连续性；（2）连续相变。[公式：见原文]和[公式：见原文]随T连续，而[公式：见原文]和[公式：见原文]在一个T点处存在不连续性；以及（3）弥散相变。[公式：见原文]和[公式：见原文]随T连续，而它们在转变温度（T）和弥散温度（T）处分别等于0。相变的弥散区域为[公式：见原文]，弥散度为[公式：见原文]，自然地给出了相变与比热峰的关系。
