Structures and Physical Properties of Ternary Antimonides RE₃MSb₅ (M = Zr, Hf), U₃MSb₅ (M = Zr, Hf, Nb), and YbCrSb₃

Abstract

Ternary rare-earth transition-metal antimonides RExMySbz have provided fertile ground for discovering materials with varied electrical and magnetic properties such as superconductivity and ferromagnetism. The properties of two important classes of these compounds, RE3TiSb5 and RECrSb3, have been previously investigated. These studies have now been extended to RE3MSb5 (M = Zr, Hf), which show anomalies in their resistivity curves suggestive of electronic transitions, and YbCrSb3, which undergoes long-range magnetic ordering at 285 K, the highest Tc observed so far of all RECrSb3 members. Strong magnetic exchange interactions develop through coupling of f and d electrons in these compounds. The substitution of uranium for rare earth in RE3MSb5 results in the compounds U3MSb5 (M = Zr, Hf, Nb), which also display prominent transitions in their electrical resistivity and magnetic susceptibility curves.

Structure and physical properties of ternary uranium transition-metal antimonides U3MSb5 (M=Zr, Hf, Nb)

“…For this reason, it was of interest to determine the physical properties of the U 3 MSb 5 series. Following on previously communicated preliminary results [10], we report here the synthesis of the new compounds U 3 MSb 5 (M = Zr, Hf, Nb), their crystal structures, and their transport and magnetic properties.…”

Ternary rare-earth titanium antimonides: Phase equilibria in the RE–Ti–Sb (RE=La, Er) systems and crystal structures of RE2Ti7Sb12 (RE=La, Ce, Pr, Nd) and RETi3(SnxSb1–x)4 (RE=Nd, Sm)

“…Further experiments to understand these synthetic difficulties are ongoing. For example, results from arc melting reactions with different loading compositions ''SmTi 3 (Sn x Sb 1Àx ) 4 '' (0oxo1 in 0.1 increments) confirmed that this phase does not form beyond xX0.2.…”

“…Given that NdTi 3 (Sn 0.1 Sb 0.9 ) 4 and SmTi 3 (Sn 0.1 Sb 0.9 ) 4 were obtained in the presence of excess Sn, these formulas represent the upper limit of Sn solubility. The lower limit of Sn solubility in RETi 3 (Sn x Sb 1Àx ) 4 was not determined, but in light of our inability to prepare ''RETi 3 Sb 4 '' as described above, it is likely that this limit does not extend to x ¼ 0. Further experiments to understand these synthetic difficulties are ongoing.…”

“…Systems containing a late transition metal have been the focus of most previous studies, whereas those containing an early transition metal remain poorly investigated. When M is a group 4, 5, or 6 element, the only compounds known so far are RE 3 MSb 5 (M ¼ Ti, Zr, Hf, Nb) [2][3][4][5], REMSb 3 (M ¼ V, Cr) [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], and REZrSb [23][24][25][26]. In the Sb-rich phases, homoatomic Sb bonding networks are a recurring feature of the structures, in the form of one-dimensional chains in RE 3 MSb 5 or two-dimensional nets in REMSb 3 .…”

“…A new ternary phase, RE 2 Ti 7 Sb 12 (RE ¼ La, Ce, Pr, Nd) has been identified and its structure determined. In addition, a pseudoternary phase, RETi 3 (Sn x Sb 1Àx ) 4 (RE ¼ Nd, Sm) was discovered in the course of crystal growth experiments. Both of these phases adopt new structure types in which Ti-centred octahedra and homoatomic Ti-Ti or Sb-Sb bonding figure prominently.…”