Magnetic Properties and Phase Transformations of Cu₅₇Ni₁₅Sn₈Mn₂₀ Alloy at Different Annealing Temperatures

This study presents a systematic investigation of the magnetic properties and phase transitions in a Cu₅₇Ni₁₅Sn₈Mn₂₀ alloy subjected to various annealing temperatures. X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM) analyses demonstrate that the precipitation of distinct phases is contingent upon the annealing temperature. Room-temperature crystal structure analysis was conducted using XRD. Microstructure observation and elemental composition testing were performed via SEM coupled with EDS. Additionally, the magnetic and electrical properties of the samples were characterized by VSM. Thermomagnetic (M-T) and isothermal magnetization (M-H) curves indicate that the magnetic properties of the alloy are markedly enhanced with decreasing annealing temperature. The alloy annealed at 873 K exhibits a room-temperature magnetization of approximately 14.5 emu/g, along with a Curie temperature (T_C) of approximately 350 K measured under an applied field of 1 kOe. Alloys annealed at 873 K exhibit low resistivity and excellent electrical conductivity. Hardness testing shows that annealing alleviates internal stresses, leading to a reduction in Vickers hardness. The imaginary component and phase of the AC magnetic susceptibility also exhibit a dependence on the annealing temperature. The present study demonstrates that the annealing temperature critically governs the magnetic properties and phase transitions in the Cu₅₇Ni₁₅Sn₈Mn₂₀ alloy. Through precise temperature modulation, these properties can be controllably tailored, thereby establishing a systematic methodology for investigating magnetic Cu-based alloys.