Tata Institute Of Fundamental Research, Bombay-400005, India.
Rep Prog Phys. 2017 Nov;80(11):116501. doi: 10.1088/1361-6633/aa7d5f.
Rare earth compounds of the type [Formula: see text] (R = rare earth; T = Rh, Ir, and X = Si, Ge, Sn) display a variety of phase transitions towards exotic states, including charge density waves (CDW), local moment magnetism, antiferromagnetism in the heavy fermion state, superconductivity and giant positive magnetoresistance. They support strongly correlated electron systems. In particular, R Ir [Formula: see text] (R = Dy-Lu) exhibit strong coupling CDWs with high transition temperatures, and superconductivity or magnetic ordering at lower temperatures. [Formula: see text] [Formula: see text] (R = Gd-Tm; T = Co, Rh, Ir) show multiple magnetic transitions with large magnetoresistance below the magnetic transitions. Finally, the light rare earth series [Formula: see text] [Formula: see text] (R = Ce, Pr, Nd; T = Rh, Ir) display heavy fermion behaviour (for Ce and Pr) or possess giant positive magnetoresistance (for Nd) at low temperatures. This review provides a comprehensive overview of compounds, crystal structures and phase transitions. This is followed by an in-depth discussion of the mechanisms of the phase transitions and the properties of the ordered states.
[化学式：见正文]型稀土化合物（R = 稀土；T = Rh、Ir，X = Si、Ge、Sn）表现出多种向奇异态的相变，包括电荷密度波（CDW）、重费米子态中的局域磁矩、反铁磁有序、超导性和巨大的正磁电阻。它们支持强关联电子系统。特别是 R Ir [化学式：见正文]（R = Dy-Lu）表现出具有高转变温度的强耦合 CDW 和较低温度下的超导性或磁有序。[化学式：见正文] [化学式：见正文]（R = Gd-Tm；T = Co、Rh、Ir）在磁转变以下表现出多个具有大磁电阻的磁转变。最后，轻稀土系列 [化学式：见正文] [化学式：见正文]（R = Ce、Pr、Nd；T = Rh、Ir）在低温下表现出重费米子行为（对于 Ce 和 Pr）或具有巨大的正磁电阻（对于 Nd）。本综述全面概述了化合物、晶体结构和相变。接着深入讨论了相变的机制和有序态的性质。
