Mossbauer Effects and Magnetic properties of Mixed Valent Europium Sulfide,EuPd_3S_4

摘要

EuPd_3S_4 with a naPt_3O_4-type structure was invetigated by X-ray diffraction,~(151)Eu Mosbauer spectroscopym,agentic susceptibility,and specific heat measurements.In this compound, Eu~(2+) and Eu~(3+) ions exist in the ratio of ca.1:1.The Debye temperatures of Eu~(2+) and Eu~(3+) were determined to be 195 and 220K,respectively.The isomer shift of Eu~(2+) sulfides because fo the compression effect of the Eu~(2+) sites.The temperature dependence of the isomer shifts suggestes that a hopping of the electron between Eu~(2+) and Eu~(3+) occurs in EuPd_3S_4.The Eu~(2+) ion was found to be in the antiferromagnetic stat ebelow 3K from both the magnetic susceptibility and specific heat measurements.