Critical magnetic behaviour of triuranium tetraphosphide U3P4

The initial susceptibility and spontaneous magnetization of U3P4 single crystals were found to follow the simple power laws, describing by the critical exponents γ, β and delta, whose values were established to be 1.19+-0.01, 0.391+-0.003 and 4.03+-0.05, respectively. The Curie temperature of U3P4 determined in different ways is equal to (137.5+-0.1) K. The obtained values of the critical exponents are exactly consistent with the scaling relation. In view of the extremely large magnetocrystalline anisotropy present in U3P4, the above values are first compared to those of similar anisotropic materials and then discussed in terms of a three dimensional Ising system. (orig.)