Crossover of the dimensionality of 3d spin fluctuations in LaCoPO
Abstract
dc magnetization and 31P spin lattice relaxation rate in the polycrystalline sample of LaCoPO suggest a spin fluctuation dominated ferromagnetically ordered state. Moreover, NMR data clearly indicate a crossover from 2D to 3D spin fluctuations across TC. In contrast to isotropic hyperfine field, Hhf at the 31P site in LaFePO, Hhf is anisotropic in LaCoPO. The data of spin lattice relaxation rate also exhibit anisotropic spin fluctuation. The anisotropy vanishes near TC.
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