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arXiv 1107.2544cond-mat.str-elcond-mat.other
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Eu $_2$ Ir $_2$ O $_7$的压力调谐绝缘体-金属转变

Pressure Tuned Insulator to Metal Transition in Eu$_2$Ir$_2$O$_7$

F. F. Tafti, J. J. Ishikawa, A. McCollam, S. Nakatsuji, S. R. Julian

摘要:

研究了压力对烧绿石铱酸盐$_2$的影响,该化合物在常压下有一个热驱动的绝缘体到金属的转变,其温度为$T_{MI}\sim120$ 1,K.作为压力的函数,绝缘间隙在接近$P \sim 6$ \,GPa时明显连续地闭合。然而,不是$T_{MI}$如预期的那样变为零,而是绝缘基态跨越到具有负电阻率温度系数的金属态,从而对两种基态的真实性质提出了疑问。高温状态也跨越了近6 GPa,从非相干到传统的金属,表明高温和低温状态之间的联系。

英文摘要:

We have studied the effect of pressure on the pyrochlore iridate Eu$_2$Ir$_2$O$_7$, which at ambient pressure has a thermally driven insulator to metal transition at $T_{MI}\sim120$\,K. As a function of pressure the insulating gap closes, apparently continuously, near $P \sim 6$\,GPa. However, rather than $T_{MI}$ going to zero as expected, the insulating ground state crosses over to a metallic state with a negative temperature coefficient of resistivity, calling into question the true nature of both ground states. The high temperature state also crosses over near 6 GPa, from an incoherent to a conventional metal, suggesting a connection between the high and the low temperature states.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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