The Structural and Magnetic Properties of CuRh1−x Mn x O2 (0 ≤ x ≤ 0.1) Delafossite Oxide

Abstract

The CuRh 1−x Mn x O 2 (0.00 ≤ x ≤ 0.10) polycrystalline powders were synthesized by the direct solidstate reaction. The magnetic susceptibility was measured in the temperature range of 4-300 K. It was found that the magnetic susceptibility (χ ) increases rapidly with the doping of Rh 3+ by Mn 3+ ions with existence of paramagnetic substance at low temperature. For x = 0.1, a development of new antiferromagnetic (AF) transition around 26 K and the magnetic data for CuRh 1−x Mn x O 2 show evidence for weak ferromagnetic (FM) transition between 100 and 130 K. Clear hysteresis loops indicate that FM order exists in Mn-doped samples at 5 K. All samples behave like semiconductors. The ferromagnetism properties can be attributed to the double-exchange interaction between the Mn 3+ and Rh 3+ semiconductor compounds. We analyze the magnetic entropy change S M of CuRh 0.9 Mn 0.1 O 2 . Using Arrott plots, it was found that the phase transition for this sample at T N = 42 K is of second order. The maximum entropy change of ∼ 0.017 J/kg K upon a filed variation of ∼ 1 T and ∼ 0.076 J/kg K upon a filed variation of ∼ 5