Magnetic Properties of Ba4Zn2Fe36O60 Single Crystals

Abstract
The dc and microwave magnetic properties of single crystals of Ba4Zn2Fe36O60(ZnU) were investigated. The saturation magnetization ‖ and ⊥ to c, anisotropy constant and anisotropy field were determined as a function of temperature from 4.2 to 600°K. TC = 673±2°K. At room temperature 4πMs = 3700 G, K1 = 1.4×106 ergs/cm3 and HA = 9.6 kOe. At 4.2°K 4πMs = 6190 G, K1 = 2.4×106 and HA = 10 kOe. A magnetic moment nβ = 60 was computed from a collinear spin model, excellent agreement with nβ = 60.5, calculated from σs(H = ∞, T = 0). This result tends to confirm allignment of spins ‖ to c. Ferrimagnetic resonance linewidths of 210 Oe were measured on unpolished samples in the range 30–40 GHz. An anisotropy in electrical resistivity of 107 Ω·cm ‖ and 4×103 Ω·cm ⊥ to c was noted.