Magnetic phase diagrams of the ferromagnetic Kondo lattice CePd2Al8

Abstract

We report the synthesis and detailed investigation of the single crystal ${\mathrm{CePd}}_{2}{\mathrm{Al}}_{8}$. Resistivity measurements reveal typical metallic behavior at high temperatures and a plateau at about 15 K followed by a rapid drop due to successive antiferromagnetic (AFM) and ferromagnetic (FM) transitions. The specific heat and magnetic susceptibility present obvious anomalies related to both transitions. We find an extremely large magnetic anisotropy with ${\ensuremath{\chi}}_{a}/{\ensuremath{\chi}}_{b}g2000$ at 2 K. With increasing magnetic field, the AFM transition temperature is gradually suppressed and only the ferromagnetic phase remains above 500 Oe for $H\ensuremath{\parallel}a$, with an ordered moment of $1.43\phantom{\rule{0.28em}{0ex}}{\ensuremath{\mu}}_{B}$, while for $H\ensuremath{\parallel}b$ the FM transition turns into an AFM-like transition. With pressure, the two phases merge at 12.5 GPa into a possibly ferromagnetic phase, pointing to a possible critical point at higher pressures. We construct the temperature-magnetic field and temperature-pressure phase diagrams for the single crystal ${\mathrm{CePd}}_{2}{\mathrm{Al}}_{8}$.