Magnetic Susceptibility Resistivity and Thermal Expansion Measurements on FeP

Susceptibility, resistivity and thermal expansion measurements have been performed on single crystals of FeP. The temperature ranges were 4.2 K-300 K, 15 K-300 K and 95 K-300 K respectively. The susceptibility measurements show a magnetic transition at 120 K, which is due to an antiferromagnetic ordering in the ab-plane. Above T N there is a considerable amount of anisotropy. The susceptibility curves representing the three principal directions have maxima around 220 K. The magnetic structure is interpreted in terms of a linear chain model. This interpretation of the experimental results is based on the theoretical work by Kallel et al. Resistivity measurements, carried out with the van der Pauw method, give an anisotropic resistivity tensor. The resistivity vs. temperature curves have points of inflexion at 115 K. The thermal expansion coefficient of the b-axis is much larger than the coefficients of the other axes.