Research on Electron Spin Resonance of La0.3 Ca0.7 Mn1-x WxO3 (x = 0.04, 0.08, 0.12) System

The polycrystalline material La0.3Ca0.7Mn1-xWxO3(x = 0.04, 0.08, 0.12) was prepared by the solid-state reaction method, ρ-T curves and ESR spectra of the samples were measured, and the normalized intensity and the linewidth of ESR spectra were studied. The results show that: When x ≤ 0.08, the ρ-T curves exhibit an inflection point, the system exhibits charge-ordering (CO) phase, and the spin order exhibits paramagnetism (PM)-charge ordering (CO)-antiferromagnetism (AFM) transition with temperature decreasing; when x = 0.12, the ρ-T curve does not exhibit the inflection point, the CO phase melts, the spin order is mainly paramagnetism (PM), and the ferromagnetic correlation strengthens at low temperature. For the samples of x ≤ 0.08, on the temperature range above TCO, the linewidth almost does not change, the system is in paramagnetic state, and the ferromagnetic correlation is comparatively weak; on the temperature range below TCO, the ferromagnetic correlation of the system strengthens, and the linewidth increases with temperature decreasing.