ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Ternary metal excess rare-earth gallides and germanides have been extensively investigated concerning their interesting physical properties with respect to magnetic and electronic correlations, such as magnetic ordering, intermediate valency, Kondo or heavy fermion behavior. A solid solution of the binary phases GdGa and GdGe was found investigating the phase equilibria in the pseudobinary system Gd-Ga-Ge at T=800 °C. Samples with the composition GdGa1−xGex (x=0, 0.1, 0.15, 0.25, 0.5) were prepared by arc melting the elements under inert atmosphere and subsequent annealing (350 h) in evacuated silica capsules. The crystal structure and unit-cell dimensions were determined by x-ray powder analyses (Guinier technique, Cu Kα1 radiation). Powder patterns were indexed on the basis of a C-centered orthorhombic unit cell. No deviations of the structure type α-ITI (CrB) have been encountered. A monotonic decrease of the unit-cell volume versus Ge concentration is observed. However, a significant decrease of the b and c parameters is thereby compensated by an increase of the a parameter. Magnetic measurements were performed by SQUID and ac techniques over a temperature range T=5–300 K and in external fields up to 6 T. All samples exhibit ferromagnetic order with slightly decreasing Tc as well as values of magnetization (at T=5 K and H=0.1 T) with increasing concentration x. However, metamagnetic transitions are revealed for all samples with x(approximately-greater-than)0. The results are discussed within the concept of indirect exchange interaction (RKKY-type interaction). © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.361297
Permalink