Dynamical properties of 119Sn in crystalline SnI4 investigated by the Mossbauer effect
Dynamical properties of 119Sn in crystalline SnI4 investigated by the Mossbauer effect
复制标题
通过穆斯堡尔效应研究晶体 SnI4 中 119Sn 的动力学性质
DOI：
10.1088/0022-3719/10/10/019
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发表时间：
1977
期刊：
影响因子：
--
通讯作者：
N. B. Olsen
中科院分区：
文献类型：
--
作者：
I. Heilmann;N. B. Olsen
在100K ~ 300K大气压和200K 2kbar大气压下测量了sn4中119Sn穆斯堡尔谱线的强度I。在低温下，lnI对温度的斜率δ与温度无关。应用具有sn4分子刚性运动的德拜模型，人们得到了一个异常低的德拜温度（θ =49K），然而，超声波测量（57K）证实了这一点。在170K以上，观察到lnI随温度的线性偏差越来越大。此外，在更高的压力下，观察到200K时穆斯堡尔强度的大幅增加。这两个观察结果表明，体积变化强烈影响晶格动力学。它们由准调和模型解释，使用格鲁尼森参数等于γ =4+或1.5。
The intensity I of the 119Sn Mossbauer line in SnI4 was measured from 100K to 300K at atmospheric pressure and at 200K at a pressure of 2 kbar. At low temperatures, the slope delta of lnI versus temperature is independent of temperature. Applying a Debye model with rigid motion of the SnI4 molecules, one obtains an unusually low value of the Debye temperature ( theta =49K) which, however, is confirmed by ultrasonic measurements (57K). Above 170K, an increasing deviation from linearity of lnI versus temperature is observed. Furthermore, at higher pressure, a large increase of the Mossbauer intensity at 200K is observed. These two observations indicate that volume changes strongly influence the lattice dynamics. They are explained by a quasiharmonic model using a Gruneisen parameter equal to gamma =4+or-1.5.