Heat capacity, resistivity, and angular dependent magnetization studies of single crystal Nd1+∊Fe4B4 for ∊≈17

Advances in crystal growth have allowed for synthesis of large single crystals of Nd1+∊Fe4B4, a well-known phase with a modulated structure. As a result we are able to report heat capacity and resistivity measurements on a single crystal Nd1+∊Fe4B4 sample with a distribution of ∊ that skews towards the solubility limit of Nd near ∊≈17. Heat capacity measurements show evidence of crystal field splitting at temperatures higher than the long-range ferromagnetic Curie temperature. Heat capacity, resistivity, and magnetization measurements all confirm a Curie temperature of 7 K which is lower than previously reported values in the Nd1+∊Fe4B4 system. We also perform measurements of the angular dependence of the magnetization and discover behavior associated with the magnetic anisotropy that is inconsistent with the simple description previously proposed.