Mehta N, Kumar A
Department of Physics, Institute of Science, Banaras Hindu University , Varanasi, India.
Department of Physics, Harcourt Butler Technological Institute , Kanpur, India.
J Phys Chem B. 2016 Feb 18;120(6):1175-82. doi: 10.1021/acs.jpcb.5b10441. Epub 2016 Feb 3.
Calorimetric study of glass/crystal phase transformation in disordered semiconductors is a significant tool for understanding their crystallization kinetics. Such studies provide the basis for practical application of glasses. Differential scanning calorimetry (DSC) is one of the advanced techniques for the analysis of thermally induced crystallization in glassy or amorphous systems. We are reporting the nonisothermal DSC measurements on four amorphous systems of Se70Te30 alloy with Ag, Cd, Sb, and Zn as chemical modifiers. In general, the rate constant (K) shows Arrhenian dependence on temperature (T), i.e., K = K0 exp (-Eg/RT) where Eg is the activation energy of crystal growth and K0 is called the pre-exponential factor of rate constant. In the present work, an experiment is designed to see the effect of composition on the activation energy of crystal growth. We have found Meyer-Neldel relation (MNR) between Eg and K0 for present systems. Another interesting feature of present work is the observation of further relation between Meyer-Neldel prefactor and Meyer-Neldel energy.
对无序半导体中玻璃/晶体相变进行量热研究是理解其结晶动力学的重要工具。此类研究为玻璃的实际应用提供了基础。差示扫描量热法(DSC)是分析玻璃态或非晶态系统中热致结晶的先进技术之一。我们报道了以Ag、Cd、Sb和Zn作为化学改性剂的Se70Te30合金的四个非晶态系统的非等温DSC测量结果。一般来说,速率常数(K)呈现出对温度(T)的阿仑尼乌斯依赖性,即K = K0 exp (-Eg/RT),其中Eg是晶体生长的活化能,K0被称为速率常数的指前因子。在本工作中,设计了一个实验来观察组成对晶体生长活化能的影响。我们发现了当前系统中Eg和K0之间的迈耶-内德尔关系(MNR)。本工作的另一个有趣特征是观察到迈耶-内德尔前因子与迈耶-内德尔能量之间的进一步关系。