Metal–Insulator Transitions in Pyrochlore Oxides Ln2Ir2O7

Bibliographic Information

Other Title
  • Metal–Insulator Transitions in Pyrochlore Oxides <i>Ln</i><sub>2</sub>Ir<sub>2</sub>O<sub>7</sub>

Search this article

Description

We report the physical properties of Ln2Ir2O7 (Ln = Nd, Sm, Eu, Gd, Tb, Dy, and Ho), which exhibit metal-insulator transitions (MITs) at different temperatures. The transition temperature TMI increases with a reduction in the ionic radius of Ln. The ionic radius boundary for MITs in Ln2Ir2O7 lies between Ln = Pr and Nd. MITs in Ln2Ir2O7 have some common features. They are second-order transitions. Under the field cool condition, a weak ferromagnetic component (»10−3 μB/f.u.) caused by Ir 5d electrons is observed below TMI.The entropy associated with MITs for Ln = Nd, Sm, and Eu is estimated to be 0.47, 2.0, and 1.4 J/K mole, respectively. The change in entropy is much smaller than 2R ln 2 [11.5 J /K mole] expected in a magnetic transition due to localized moments of S = 1/2. The feature of continuous MITs in Ln2Ir2O7 is discussed.

Journal

Citations (69)*help

See more

References(30)*help

See more

Related Projects

See more

Details 詳細情報について

Report a problem

Back to top