The structure, Raman spectroscopy and evidence of ferromagnetic transition in CuCr1−xMxO2 (M=Mn and Rh) compounds

•Mn replacement of the Cr in the magnetic frustrated CuCrO2.•Mn3+/Mn4+ generate anisotropic microstrains in the structure.•Mn substitutions lead to an increase of the susceptibilities magnetic.•The incorporation of Mn3+/Mn4+ in CuCrO2 induced weak ferromagnetic interactions at low temperature.

The CuCr1−xMxO2 (M=Mn, Rh) polycrystalline powders were synthesized by the direct solid state reaction of Cu2O and M2O3 (M=trivalent cation or mixer of trivalent cation for transition metal). The magnetic susceptibility was measured in the temperature range of 0–300 K. It was found that the magnetic susceptibility (χ) increases rapidly with the doping of Cr3+ by Mn3+ and Rh3+ ions with existence of paramagnetic substance at low temperature. With the substitution of magnetic Mn3+ and Rh3+ for Cr3+ (S=3/2), the antiferromagnetic (AF) transition becomes broader and the transition temperature increases. However, at low temperature, the magnetic data for CuCr1−xMxO2 (M=Mn, Rh) show evidence for weak ferromagnetic (FM) transition between 100 K and 130 K. Clear hysteresis loops indicate that FM order exists in both of them Mn or Rh-doped samples at 4 K. All samples behave like semiconductors. The ferromagnetism properties can be attributed to the double exchange interaction between the Mn3+ or Rh3+ and Cr3+ semiconductors compounds.