Structural, magnetic and thermal properties of CaMn0.99Fe0.01O3-delta

The polycrystalline CaMn0.9957Fe0.01O3-delta compound was studied using powder X-ray diffraction, 57Fe Mossbauer spectroscopy, ac susceptometry, dc magnetometry, specific heat and electrical resistivity measurements. X-ray diffraction measurements performed between 70 and 300K show a thermal expansion anomaly at the Neel temperature. A weak ferromagnetic component and a spin-glass behaviour below Neel temperature are found in magnetic measurements. The Mossbauer spectroscopy measurements performed between 30 and 300K provided the Neel temperature value of 118K, the same as obtained from dc magnetisation and close to that derived from the specific heat (119K). 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.