MÖSSBAUER SPECTROSCOPY OF METAL SANDWICH COMPOUNDS *
MÖSSBAUER SPECTROSCOPY OF METAL SANDWICH COMPOUNDS *
复制标题
金属夹层化合物的穆斯堡尔谱*
DOI：
--
复制
发表时间：
1974
影响因子：
5.2
通讯作者：
D. Foyt
中科院分区：
文献类型：
--
作者：
M. Good;John Buttone;D. Foyt
穆斯堡尔谱学在化学问题中的应用包括两个步骤：从实验数据中提取基本的穆斯堡尔参数（同质异能素位移、原子核处的电场梯度张量等），并根据结构和成键解释这些参数。在铁光谱的特殊情况下，同质异能差和四极分裂参数的提取相对简单，因为穆斯堡尔跃迁中的Ipw核自旋态产生相当简单的光谱。在核处没有电场梯度的情况下，I = 3/2到I = 1/2的跃迁被观察为单线共振，其中异构体位移反映了吸收核的化学（电子）环境的影响。穆斯堡尔效应是通过允许来自激发核衰变的伽马射线被感兴趣的吸收体基质中的相同核（处于基态）共振吸收来观察的。同质异能素位移的产生是由于源中穆斯堡尔核素的电子环境。和吸收体不同;因此，与原子核能级的静电相互作用使得从源发射的伽马射线的能量与吸收体中共振吸收所需的能量略有不同。光谱是通过安装光源而形成的。在一个可移动的驱动器和“扫描”的能量范围内的利益通过多普勒效应。因此，通常的穆斯堡尔谱显示为计数（伽马射线密度）与速度（直接与多普勒效应对伽马射线的能量扰动成正比）。异构体位移定义为：
The application of Mossbauer spectroscopy to problems of chemical interest involves two steps: the extraction of the basic Mossbauer parameters (isomer shift, electric field gradient tensor at the nucleus, and so forth) from the experimental data and the interpretation of these parameters in terms of structure and bonding. In the special case of iron spectroscopy, the extraction of the isomer shift and quadrupole splitting parameters is relatively straightforward because Ipw nuclear spin states in the Mossbauer transition give rise to rather simple spectra. In the absence of an electric field gradient at the nucleus, the I = 3/2 to I = 1/2 transition is observed as a single line resonance where the isomer shift reflects the effect of the chemical (electronic) environment of the absorbing nucleus. The Mossbauer effect is observed by allowing the gamma’ rays from the decay of an excited nucleus to be resonantly absorbed by the same nucleus (in the ground state) in an absorber matrix of interest. The isomer shift arises from the fact that the electronic environments of the Mossbauer nuclide in the source. and absorber are different; thus, electrostatic interactions with the nuclear levels are such that the energy of the emitted gamma ray from the source is slightly different from the energy required for resonance absorption in the absorber. The spectrum is developed by mounting the source. on a movable drive and “scanning” the energy range of interest by means of the Doppler effect. Thus, the usual Mossbauer spectrum is displayed as counts (gamma ray density) vs velocity (directly proportional to the energy perturbation of the gamma rays by the Doppler effect). The isomer shift is defined as: