Temperature-dependent magnetization (M(T)) and specific heat (CP(T)) measurements were carried out on single-crystal Sm1.85Ce0.15CuO4-δ (TC=16.5K). The magnetic anisotropy in the static susceptibility, x = M/H, is apparent not only in its magnitude but also in its temperature dependence, with Χ⊥ for H ⊥ c larger than Χ∥ for H ∥ c. For both field orientations, Χ does not follow the Curie-Weiss behavior due to the small energy gap of the J = 7/2 multiplet above the J = 5/2 ground-state multiplet. However, with increasing temperature, Χ∥(T) exhibits a broad minimum near 100 K and then a slow increase while Χ⊥(T) shows a monotonic decrease. A sharp peak in CP(T) at 4.7 K manifests an antiferromagnetic ordering. The electronic contribution, 7, to CP(T) is estimated to be γ = 103.2 (7) mJ/mole·Sm·K2. The entropy associated with the magnetic ordering is much smaller than Rln2, where R is the gas constant, which is usually expected for the doublet ground state of Sm+3. The unusual magnetic and electronic properties evident in M(T) and CP(T) are probably due to a strong anisotropic interaction between conduction electrons and localized electrons at Sm+3 sites.
Bibliographical noteFunding Information:
This work was supported by the Korea Science & Engineering Foundation through the grant No. 1999-2-114-005-5.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering