We studied the electrical resistance and crystal structure of epitaxial chromium (Cr) films. The lattice constant of the Cr films was larger than that of the bulk Cr because of MgO substrate on which ...Cr was epitaxially deposited. A chromium oxide layer having a thickness of 1 nm was found on all films from the result of X-ray reflectivity measurements. The electrical resistivity ρ(T) shows metallic behavior for all epitaxial Cr films in contrast with polycrystalline one. However, the magnitude of ρ tends to increase and the antiferromagnetic interaction is suppressed as decreasing thickness of film.
We studied the electrical resistance of single-crystal and polycrystalline chromium films. The ρ(T) curve of single-crystal films decrease with decreasing temperature and show humps at around 300 K ...consistent with the bulk chromium being an itinerant antiferromagnet. In the polycrystalline films, on the other hand, the ρ(T) curves deviate from those of the bulk chromium. Moreover, we observed sudden decrease in the resistance around 1.5 K. Although previous studies suggested that chromium films become superconductive (Schmidt et al. (1972) 12), it is difficult to conclude whether a superconducting transition occurs because the electrical resistivity is not zero in all films. No anomaly was detected by resistance measurements around room temperature, and the sudden decrease in the resistance at low temperature may be attributed to the suppression of antiferromagnetic interaction by thinning down the chromium element.
•The electrical resistance measurements were performed in several chromium films.•We observed sudden decrease in the resistance around 1.5 K, but the electrical resistivity is not zero in all films.•It is difficult to conclude whether a superconducting transition occurs contrary to the previous reports.
We have carried out high-angle X-ray powder diffraction measurements of the caged magnetic compound DyFe2Zn20 at low temperature between 14 and 300K. Even though a strong magnetic anisotropy exists ...in the magnetization and magnetic susceptibility due to strong exchange interaction between Fe and Dy, almost all X-ray powder diffraction peaks correspond to Bragg reflections of the cubic structural models not only at room temperature paramagnetic state but also at low temperature magnetic ordering state. The Debye temperature is obtained to be 227K from the results of the volumetric thermal expansion coefficient, which is approximately coincident with that of CeRu2Zn20 (245K) and that of pure Zn metal (235K).
We have carried out high-angle X-ray powder diffraction measurements of the caged magnetic compound DyFe2Zn20 at low temperature between 14 and 300 K. Even though a strong magnetic anisotropy exists ...in the magnetization and magnetic susceptibility due to strong exchange interaction between Fe and Dy, almost all X-ray powder diffraction peaks correspond to Bragg reflections of the cubic structural models not only at room temperature paramagnetic state but also at low temperature magnetic ordering state. The Debye temperature is obtained to be 227 K from the results of the volumetric thermal expansion coefficient, which is approximately coincident with that of CeRu2Zn20 (245 K) and that of pure Zn metal (235 K).
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