Magnetic properties of the intermetallic compound Ce<inf>5</inf>Ge<inf>4</inf>

Magnetic and magnetocaloric properties of the compound Ce5Ge4 have been studied. This compound has orthorhombic Sm5Ge4-type structure (space group Pnma, no. 62) and orders ferromagnetically at ~12 K (TC). The paramagnetic Curie temperature is ~-20 K suggesting the presence of competing ferromagnetic and antiferromagnetic interactions in this compound. The magnetization does not seem to saturate even in fields of 90 kOe at 3 K consistent with the presence of competing interactions. Saturation magnetization value (extrapolated to 1/H→0) of only 0.8μB/Ce3+ is obtained compared to the free ion value of 2.14μB/Ce3+. This moment reduction in the ordered state of Ce5Ge4 could be due to partial antiferromagnetic/paramagnetic ordering of the Ce moments and may also be due to crystalline electric field effects. Magnetic entropy change near TC, calculated from the magnetization vs. field data, is found to be moderate with a maximum value of ~9 J/kg/K at ~11 K for a field change of 90 kOe. © 2009 Elsevier B.V. All rights reserved.