Anisotropic magnetic and transport properties of orthorhombic o-Pr₂Co₃Ge₅

Abstract The crystal structure, electron energy-loss spectroscopy (EELS), heat capacity, and anisotropic magnetic and resistivity measurements are reported for Sn flux grown single crystals of orthorhombic Pr₂Co₃Ge₅ (U₂Co₃Si₅-type, Ibam). Our findings show that o-Pr₂Co₃Ge₅ hosts nearly trivalent Pr ions, as evidenced by EELS and fits to temperature dependent magnetic susceptibility measurements. Complex magnetic ordering with a partially spin-polarized state emerges near T _sp = 32 K, with a spin reconfiguration transition near T _M = 15 K. Heat capacity measurements show that the phase transitions appear as broad peaks in the vicinity of T _sp and T _M. The magnetic entropy further reveals that crystal electric field splitting lifts the Hund’s rule degeneracy at low temperatures. Taken together, these measurements show that Pr₂Co₃Ge₅ is an environment for complex f state magnetism with potential strongly correlated electron states.