Magnetic structure and enhancedTNof the rare-earth intermetallic compoundTbRhIn5: Experiments and mean-field mode

Abstract

In this work the physical properties of the intermetallic compound TbRhIn 5 were investigated by means of temperature-dependent magnetic susceptibility, electrical resistivity, heat-capacity, and resonant x-ray magnetic diffraction experiments. TbRhIn 5 is an intermetallic compound that orders antiferromagnetically at T N = 45.5 K, the highest ordering temperature among the existing RRhIn 5 ͑1-1-5, R = rare earth͒ materials, which in contrast to what is expected from a de Gennes scaling along the RRhIn 5 series. The x-ray resonant diffraction data have allowed us to solve the magnetic structure of TbRhIn 5 . Below T N , we found a commensurate antiferromagnetic structure with a propagation vector ͑1/2,0,1/2͒ and the Tb moments oriented along the c axis. Strong ͑over two orders of magnitude͒ dipolar enhancements of the magnetic Bragg peaks were observed at both Tb absorption edges L II and L III , indicating a fairly high polarization of the Tb 5d levels. Using a mean-field model including an isotropic first-neighbor exchange interaction ͑J R-R ͒ and the tetragonal crystalline electrical field ͑CEF͒, we evaluate the influence of the CEF effects in the physical properties of TbRhIn 5 . The results reported here seem to corroborate a general trend of CEF-driven effects on T N along the RRhIn 5 series.

Cd doping effects in the heavy-fermion compoundsCe2MIn8(M=Rha

“…For both materials, the magnetic susceptibility is larger for a field applied along the c axis, in agreement to what was found for the compounds in the In-based R m M n In 3m+2n ͑M = Co, Rh, or Ir, M =1,2͒ series ͑except for R =Gd͒. [24][25][26][27][28] For the whole series, the susceptibility is anisotropic and the ratio ʈ / Ќ taken at T N is mainly determined by the tetragonal crystalline electrical field ͑CEF͒ and reflects to some extent the CEF anisotropy. The ratio remains nearly constant as a function of Cd doping for each family, for example, for M = Rh the values of the ratio are roughly 1.6 and 1.5 for the samples with x = 0.21 and 0.03, respectively.…”

“…͑1͒-͑3͒. 26,33,[35][36][37][38] For this determination, we used the data obtained for ͑-Ј͒ polarization channel measured with incident photons in the energy of the Ce L 2 edge and T = 2.0 K. For this channel, the component of the matrix used was the term −kЈ · ẑ n of the Eq. ͑2͒.…”

La-dilution effects in antiferromagneticTbRhIn5single crystals

“…In this sense, the study of structurally related compounds within the R m M n In 3m+2n family has been successfully used to understand the evolution of 4f-electron magnetism for many members of the series in situations where some of the contributions above can be negligible. [21][22][23][24][25][26][27][28] For instance, in the Gd m M n In 3m+2n ͑M = Rh and Ir͒ compounds, as Gd 3+ is a pure ͑S =7/ 2,L =0͒ spin ion, the RKKY interaction and its dependence with electronic structure is the main contribution. [22][23][24] For the Nd-and Tb-based members of the R m M n In 3m+2n family, 21,25,26,28,29 both RKKY interaction and CEF effects are present, and the CEF contribution can be evaluated for Krammers ͑Nd 3+ , J =9/ 2͒ and non-Krammers ions ͑Tb 3+ , J =6͒ without the complexity of the Kondo lattice behavior of the Ce-based compounds.…”

Low temperature magnetism of Cd-doped Ce2RhIn8 heavy fermion antiferromagnet

“…In principle, fits to the integrated intensities of all magnetic peaks can be used to determine the magnetic moment direction [23,[26][27][28][29]. However, in some cases the number and intensity of the measured magnetic peaks is not enough to unambiguously determine the direction of moment.…”