12035-23-3Relevant articles and documents
Phase transitions of LnSb (Ln = lanthanide) with NaCl-type structure at high pressures
Hayashi,Shirotani,Tanaka,Adachi,Shimomura,Kikegawa
, p. 561 - 565 (2000)
Using synchrotron radiation, X-ray diffraction patterns of LnSb (Ln = Pr, Nd, Sm, Gd and Tb) with a NaCl-type structure have been measured up to 30 GPa at room temperature. First-order phase transitions with a crystallographic change occur at around 13 GPa for PrSb and 15 GPa for NdSb. The structure of the high-pressure phases of both antimonides is tetragonal (Ln: 0,0,0; Sb: 1/2, 1/2, 1/2; space group P4/mmm), and can be viewed as a distorted CsCl structure. The structure of the high-pressure phase of LnSb (Ln = La, Ce, Pr and Nd) is more anisotropic compared with that of corresponding LnP. Pressure-induced phase transitions of SmSb, GdSb and TbSb are observed at around 19, 22 and 21 GPa, respectively.
Evers, Christoph B. H.,Jeitschko, Wolfgang,Boonk, Ludger,Braun, Dieter J.,Ebel, Thomas,Scholz, Udo D.
, p. 184 - 189 (1995)
Riani, P.,Marazza, R.,Zanicchi, G.,Cacciamani, G.,Ferro, R.
, p. L11 - L14 (1993)
Magnetic properties of alkaline earth and lanthanoid iron antimonides AFe4Sb12 (A = Ca, Sr, Ba, La-Nd, Sm, Eu) with the LaFe4P12 structure
Danebrock, Martin E.,Evers, Christoph B. H.,Jeitschko, Wolfgang
, p. 381 - 387 (1996)
The magnetic properties of the nine title compounds were studied by magnetic susceptibility measurements with a SQUID magnetometer between 2 and 300K. At temperatures above 100 K, all compounds with the exception of the cerium and samarium compounds show Curie-Weiss behaviour. The effective magnetic moments of the alkaline earth compounds vary between 3.7 ± 0.2 μB and 4.0 ± 0.2 μB per formula unit. For LaFe4Sb12 the moment is smaller (3.0 ± 0.2 μB) indicating a higher degree of electronic saturation within the Fe4Sb12 polyanion. At lower temperatures, the magnetic susceptibilities of these compounds deviate from the Curie-Weiss law, however, they remain field independent. A mixed valent behaviour is observed for the cerium compound and the samarium compound reflects the Van Vleck paramagnetism of the Sm3+ ions. The magnetic susceptibilities of the other lanthanoid compounds correspond to the sums of the susceptibilities of the Fe4Sb12 polyanion and the Ln3+ and Eu2+ ions, respectively. These antimonides order ferromagnetically with Curie temperatures varying between 5(1) K for PrFe4Sb12 and 82(2) K for EuFe4Sb12. The magnetic properties of these compounds are discussed within the framework of a rigid band structure.
Synthesis and Transport Properties of the Family of Zintl Phases Ca3RESb3(RE = La-Nd, Sm, Gd-Tm, Lu): Exploring the Roles of Crystallographic Disorder and Core 4f Electrons for Enhancing Thermoelectric Performance
Ogunbunmi, Michael O.,Baranets, Sviatoslav,Bobev, Svilen
, p. 9382 - 9392 (2021/12/13)
Zintl phases with complex crystal structures have been studied as promising candidate materials for thermoelectric (TE) applications. Here, we report the syntheses of the family of rare-earth metal Zintl phases with the general formula Ca4-xRExSb3 (x ≈ 1; RE = La-Nd, Sm, Gd-Tm, Lu). The structural elucidation is based on refinements of single-crystal X-ray diffraction data for 12 unique chemical compositions. The cubic structure is confirmed as belonging to the anti-Th3P4 structure type (space group I4ˉ 3d, no. 220, Z = 4), where the Ca and RE atoms share the same atomic site with ca. 75 and 25% occupancies, respectively. Such crystallographic disordering of divalent Ca and trivalent RE atoms in the structure provides a pathway to intricate bonding. The latter, together with the presence of heavy elements such as Sb and the lanthanides, are expected to enhance the scattering probability of phonons, thereby leading to low thermal conductivity κ comparable to that of the ordered RE4Sb3. The drive of the hypothetical parent compound Ca4Sb3 to be stabilized by alloying with rare-earth metals can be understood following the Zintl-Klemm concept, as the resultant formula may be rationalized as (Ca2+)3RE3+(Sb3-)3, indicating the realization of closed-shell electronic configurations for all elements. This notion is confirmed by electronic structure calculations, which reveal narrow bandgaps Eg = 0.77 and 0.53 eV for Ca3LaSb3 and Ca3LuSb3, respectively. In addition, the incorporation of RE atoms into the structure drives the phase into a state of a degenerate semiconductor with dominant hole charge carriers.
