Structural, magnetic and thermal properties of CaMn 0.9957Fe 0.01O 3− δ

Abstract

The polycrystalline CaMn 0.99 57Fe 0.01O 3− δ compound was studied using powder X-ray diffraction, 57Fe Mössbauer spectroscopy, ac susceptometry, dc magnetometry, specific heat and electrical resistivity measurements. X-ray diffraction measurements performed between 70 and 300 K show a thermal expansion anomaly at the Neél temperature. A weak ferromagnetic component and a spin-glass behaviour below Neél temperature are found in magnetic measurements. The Mössbauer spectroscopy measurements performed between 30 and 300 K provided the Neél temperature value of 118 K, the same as obtained from dc magnetisation and close to that derived from the specific heat (119 K). The temperature evolution of the Fe hyperfine field was analysed within a molecular field model and revealed equal strengths of the Fe–Mn and Mn–Mn exchange interactions in this compound.