UGC-DAE Consortium for Scientific Research, Indore, India.
J Phys Condens Matter. 2012 Sep 19;24(37):376001. doi: 10.1088/0953-8984/24/37/376001. Epub 2012 Aug 23.
Temperature-dependent (57)Fe Mössbauer spectroscopy (5-723 K) and neutron diffraction (2-290 K) measurements are carried out on polycrystalline magnetoelectric GaFeO(3). From the neutron diffraction data, evidence for the magnetostriction and increased disorder at Fe sites close to the ferrimagnetic Curie transition temperature (T(C)) is observed. From the Mössbauer data, it is observed that the Lamb-Mössbauer factor as a function of temperature f(T), which is related to the integral over the first Brillouin zone of the phonon spectrum, shows a unequivocal variation at the T(C). The observations are discussed in terms of spin-phonon coupling. The observed average hyperfine fields from (57)Fe Mössbauer spectra match with the bulk magnetization data. A critical exponent (β) of 0.38 ± 0.02 and a Debye temperature (θ(D)) of ~350 K is estimated from the (57)Fe Mössbauer data.
对多晶铁电 GaFeO(3)进行了温度依赖的(57)Fe Mössbauer 光谱（5-723 K）和中子衍射（2-290 K）测量。从中子衍射数据中观察到，在接近铁磁共振居里温度（T(C)）的 Fe 位处存在磁致伸缩和增加的无序。从 Mössbauer 数据中观察到，作为温度函数的 Lamb-Mössbauer 因子 f(T)与声子谱的第一布里渊区的积分有关，在 T(C)处表现出明确的变化。这些观察结果是根据自旋-声子耦合来讨论的。从(57)Fe Mössbauer 谱中观察到的平均超精细场与体磁化数据相匹配。从(57)Fe Mössbauer 数据估计出临界指数（β）为 0.38 ± 0.02 和德拜温度（θ(D)）为~350 K。
