RE2MAl6Si4（RE = 钆、铽、镝；M = 金、铂）：具有由铝助熔剂生长的CaAl2Si2型和YNiAl4Ge2型板层的层状四元金属间化合物。

RE2MAl6Si4 (RE = Gd, Tb, Dy; M = Au, Pt): layered quaternary intermetallics featuring CaAl2Si2-type and YNiAl4Ge2-type slabs grown from aluminum flux.

作者信息

Latturner Susan E, Bilc Daniel, Mahanti S D, Kanatzidis Mercouri G

机构信息

Department of Chemistry and Department of Physics, Michigan State University, East Lansing, Michigan 48824.

出版信息

Inorg Chem. 2003 Dec 1;42(24):7959-66. doi: 10.1021/ic0346432.

DOI:10.1021/ic0346432

PMID:14632514

Abstract

Six new intermetallic aluminum silicides--Gd(2)PtAl(6)Si(4), Gd(2)AuAl(6)Si(4), Tb(2)PtAl(6)Si(4), Tb(2)AuAl(6)Si(4), Dy(2)PtAl(6)Si(4), and Dy(2)AuAl(6)Si(4)--have been obtained from reactions carried out in aluminum flux. The structure of these compounds was determined by single-crystal X-ray diffraction. They form in space group Rthremacr;m with cell constants of a = 4.1623(3) A and c = 51.048(5) A for the Gd(2)PtAl(6)Si(4) compound. The crystal structure is comprised of hexagonal nets of rare earth atoms alternating with two kinds of layers that have been observed in other multinary aluminide intermetallic compounds (CaAl(2)Si(2) and YNiAl(4)Ge(2)). All six RE(2)MAl(6)Si(4) compounds show antiferromagnetic transitions at low temperatures (T(N) < 20 K); magnetization studies of the Dy compounds show metamagnetic behavior with reorientation of spins at 6000 G. Band structure calculations indicate that the AlSi puckered hexagonal sheets in this structure are electronically distinct from the other surrounding structural motifs.

摘要

通过在铝熔剂中进行反应，已获得六种新型金属间硅化铝化合物——钆（Gd）₂铂铝₆硅₄、钆₂金铝₆硅₄、铽（Tb）₂铂铝₆硅₄、铽₂金铝₆硅₄、镝（Dy）₂铂铝₆硅₄和镝₂金铝₆硅₄。这些化合物的结构通过单晶X射线衍射确定。对于钆₂铂铝₆硅₄化合物，它们以空间群R3̅m形成，晶格常数a = 4.1623(3) Å，c = 51.048(5) Å。晶体结构由稀土原子的六边形网与在其他多元铝化物金属间化合物（钙铝₂硅₂和钇镍铝₄锗₂）中观察到的两种层交替组成。所有六种RE₂MAl₆Si₄化合物在低温下（TN < 20 K）都表现出反铁磁转变；镝化合物的磁化研究表明，在6000 G时自旋重新取向呈现变磁行为。能带结构计算表明，该结构中的铝硅褶皱六边形片在电子性质上与其他周围结构单元不同。