Unusual magnetic and structural transformations of DyFe4Ge2
Physical Review B
Magnetization of DyFe 4 Ge 2 measured as function of temperature in 1kOe magnetic field indicates antiferromagnetic (AFM) ordering at T N =62 K followed by two spin reorientation transitions at T f1 =52 K and T f2 =32 K and one unusual anomaly at 15 K (T f3 ). Three transitions (T f1 , T f2 , and T N ) are further confirmed by heat-capacity measurement in a zero magnetic field. The two low temperature magnetic transitions are broadened and gradually vanish when the applied magnetic field
... gnetic field exceeds 30 kOe, and the AFM transition shifts toward low temperature with increasing magnetic field. Reentrant magnetic glassy state is observed below freezing point T f3 = 15 K. Two field-induced metamagnetic phase transitions are observed between 2 and 50 K in fields below 140 kOe. The temperature-magnetic field phase diagram has been constructed. The first principles electronic structure calculations show that the paramagnetic tetragonal structure of DyFe 4 Ge 2 is stable at high temperature. The calculations with collinear Dy spins confirm ferrimagnetic orthorhombic DyFe 4 Ge 2 as the ground state structure, which is experimentally a stable structure with applied magnetic field. PACS Nos: 61.50.Ks, 71.20.Eh, 71.15.Mb Rare earth-based intermetallic compounds continue to draw considerable attention due to their importance in understanding of fundamental structure-property relationships, and potential for practical applications based on a variety of phenomena, including strong magnetocaloric, magnetoelastic, magnetoresistance and other effects.