TY - JOUR
T1 - Transport and magnetic properties of NdCuGe compound
AU - Goruganti, V.
AU - Rathnayaka, K. D.D.
AU - Ross, Joseph H.
AU - Öner, Y.
AU - Lue, C. S.
AU - Kuo, Y. K.
N1 - Funding Information:
This work was supported by the Robert A. Welch Foundation (Grant No. A-1526) and the National Science Foundation (DMR-0315476).
PY - 2008
Y1 - 2008
N2 - Electrical resistivity, heat capacity, and dc magnetization measurements were performed on the Al B2 -type intermetallics NdCuGe and LaCuGe over the temperature range of 2-300 K. NdCuGe exhibits magnetization attributable to Nd3+ moments, with an antiferromagnetic (AF) transition at 3.1 K. Magnetization, heat capacity, and resistivity measurements were used to determine the crystalline electric field (CEF) splitting of the Nd3+ magnetic sublevels. The ground state is a doublet composed of ±52 levels and the AF state is built from this magnetic doublet, with a reduction in the average sublattice magnetization attributable to site disorder among Cu-Ge sites. Low-temperature electrical transport is dominated by spin-disorder scattering among CEF-split levels and a small T2 spin fluctuation term. The latter is nearly two orders of magnitude smaller than previously observed in isostructural CeCuGe, for which the anomalous observed thermopower exponent was attributed to extended spin fluctuations above the magnetic transition. By contrast, simple-metallic behavior provides a good fit to the NdCuGe thermopower, thus, the CeCuGe results can be attributed to resonant scattering due to partial hybridization of the localized orbitals.
AB - Electrical resistivity, heat capacity, and dc magnetization measurements were performed on the Al B2 -type intermetallics NdCuGe and LaCuGe over the temperature range of 2-300 K. NdCuGe exhibits magnetization attributable to Nd3+ moments, with an antiferromagnetic (AF) transition at 3.1 K. Magnetization, heat capacity, and resistivity measurements were used to determine the crystalline electric field (CEF) splitting of the Nd3+ magnetic sublevels. The ground state is a doublet composed of ±52 levels and the AF state is built from this magnetic doublet, with a reduction in the average sublattice magnetization attributable to site disorder among Cu-Ge sites. Low-temperature electrical transport is dominated by spin-disorder scattering among CEF-split levels and a small T2 spin fluctuation term. The latter is nearly two orders of magnitude smaller than previously observed in isostructural CeCuGe, for which the anomalous observed thermopower exponent was attributed to extended spin fluctuations above the magnetic transition. By contrast, simple-metallic behavior provides a good fit to the NdCuGe thermopower, thus, the CeCuGe results can be attributed to resonant scattering due to partial hybridization of the localized orbitals.
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U2 - 10.1063/1.2904856
DO - 10.1063/1.2904856
M3 - Article
AN - SCOPUS:42149094390
VL - 103
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 7
M1 - 073919
ER -