Complex transport and magnetism in inhomogeneous mixed valence Ce3Ir4Ge13
Abstract
We report the discovery of Ce3Ir4Ge13 , a Remeika phase with a complex array of structural, electronic, and magnetic properties. Our single crystal x-ray diffraction measurements show that Ce3Ir4Ge13 forms in the tetragonally distorted I 41/a m d space group, which has three distinct rare earth sites. The electrical resistivity is almost temperature independent over three decades in temperature, from 0.4 K to 400 K, while the Hall coefficient measurements are consistent with a low-carrier semimetal. Magnetic susceptibility measurements reveal an effective moment, μeffexp=1.87 μB/Ce , that falls significantly short of the expected value for Ce3 +, suggesting that two of the rare earth sites are occupied by magnetic Ce3 + while the third is occupied by nonmagnetic Ce4 +. Upon cooling, Ce3Ir4Ge13 first enters a short range magnetically ordered state below TSRO=10 K , marked by a deviation from Curie-Weiss behavior in susceptibility and a broad field-independent heat capacity anomaly. At lower temperatures, we observe a second, sharper peak in the heat capacity at T*=1.7 K , concurrent with a splitting of the field-cooled and zero-field-cooled susceptibilities. A small resistivity drop at T* suggests a loss of spin disorder scattering consistent with a magnetic ordering or spin freezing transition. Ce3Ir4Ge13 is therefore a rare example of an inhomogeneous mixed valence compound with a complex array of thermodynamic and transport properties.
- Publication:
-
Physical Review Materials
- Pub Date:
- November 2019
- DOI:
- 10.1103/PhysRevMaterials.3.114407
- arXiv:
- arXiv:1910.10764
- Bibcode:
- 2019PhRvM...3k4407H
- Keywords:
-
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Materials Science
- E-Print:
- 8 pages, 6 figures, accepted for publication in Phys. Rev. Materials