Anisotropic magnetic properties of light rare-earth diantimonides

Abstract

Results are presented of anisotropic temperature and field-dependent magnetization M (H,T) and resistivity (H,T) measurements on high quality single crystals of the light rare-earth diantimonides RSb 2 , RϭLa-Nd, Sm. All of these, excepting LaSb 2 , magnetically order at low temperatures, and for CeSb 2 and NdSb 2 several magnetically ordered phases were observed in low-field magnetization and zero-field resistivity measurements. For RϭCe-Sm strong anisotropies, associated with crystalline electric field ͑CEF͒ splitting of the R 3ϩ ion, were found in M (T) measurements both below and above magnetic ordering temperatures. Furthermore, for RϭCe-Nd metamagnetic transitions were observed in M (H) and (H) for Hʈ(ab) in the magnetically ordered state. In addition, above 15 kG de Haas-van Alphen oscillations are observed for SmSb 2 and Shubnikov-de Haas quantum oscillations are observed above ϳ120 kG for NdSb 2 and SmSb 2 . The zero-field in-plane resistivity ab of all of the compounds is metallic (d/dTϾ0), with residual resistance ratios ranging from 40 to 750. The c-axis resistivity is also metallic, but appears to be considerably larger than the in-plane value, consistent with the diantimonides being quasi-two-dimensional materials. The magnetoresistance of all members of the series is large, approximately linear in H at moderate fields, and is also dependent on the relative orientation of the applied magnetic fields to the crystallographic axes. The extreme case of SmSb 2 has ͓(55 kG)Ϫ(0)]/(0)Ͼ50 000% at Tϭ2 K and Hʈc. ͓S0163-1829͑98͒03621-2͔

Charge density wave in layeredLa1−xCexSb2

“…For instance, the superconducting gap is broadened, with states at the Fermi level and the resistive transition is very wide. Above the critical field in the normal phase, the resistivity of LaSb 2 increases approximately linearly with the magnetic field up to 45 T when the field is applied along the c axis [2,3]. This is at odds with the usual magnetoresistance behavior of metals, which gives a quadratic field dependence that saturates at high magnetic fields [8,9].…”

“…These systems also present, as LaSb 2 , large and unsaturating magnetoresistances [2]. In LaAgSb 2 , the CDW was observed in thermodynamic and transport measurements, in x-ray scattering experiments, and studied as a function of substitution [20][21][22].…”

“…1). LaSb 2 is the only compound in the RSb 2 series showing superconducting properties [2]. These are still unclear, presenting several features that differ from the behavior expected in a simple s-wave BCS superconductor [3][4][5][6][7].…”

“…High-quality samples of centimeter sizes with low residual resistivity can be obtained using solution growth [1,2]. RSb 2 crystallize in the orthorhombic SmSb 2 structure (Fig.…”

Magnetization and transport properties of single crystalline RPd2P2 (R=Y, La–Nd, Sm–Ho, Yb)

“…7(b)), it is clear that the paramagnetic susceptibility of SmPd 2 P 2 does not follow a CW law up to 300K, and appears to saturate roughly at room temperature. Similar behavior has been reported for other Sm bearing compounds [25,[27][28][29]. A likely explanation for this could be thermal population of the Sm 3+ 's Hund's rule excited states.…”