Growth, structure and characterization of physico-chemical and magnetic properties of CdCr2Se4:Mn single crystals

Highlights: • The semiconducting single crystals Cd_xMn_yCr_zSe₄ were obtained using CVT-method. • The magnetic parameters are characteristic for soft ferromagnetic materials. • Specific heat measurements at strong magnetic field showed ferromagnetic order. • The DSC/TG measurements confirmed the thermal stability of obtained crystals. Crystal structure, magnetic and specific heat measurements, electrical conductivity, as well as DSC/TG measurements for single-crystalline Cd_xMn_yCr_zSe₄ (where x + y + z ≈ 3) spinels are presented. The electrical conductivity and dc magnetic susceptibility measurements exhibit thermally activated semiconducting properties and ferromagnetic (FM) order for all compositions below the Curie temperature T_C = 130 K, respectively. The long-range FM interactions, defined by the Curie temperature, do not substantially depend on the manganese content, and the nearest neighbour FM interactions, represented by the positive value of the Curie-Weiss temperature, decrease from 183 K to 156 K. Hysteresis loops of all crystals have a very small coercive field (∼18 Oe) and remanence (∼0.09 μ_B/f.u.) with full saturation above 10 kOe. These effects are interpreted in terms of the superexchange integrals for the first two coordination spheres including spin defects.