Glasslike thermal properties and isotope effect in Rb1-x(NH4)xH2PO4 mixed crystals.
Glasslike thermal properties and isotope effect in Rb1-x(NH4)xH2PO4 mixed crystals.
复制标题
Rb1-x(NH4)xH2PO4 混合晶体的玻璃状热性质和同位素效应。
DOI：
10.1103/physrevlett.67.93
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发表时间：
1991
影响因子：
8.6
通讯作者：
Courtens
中科院分区：
文献类型：
--
作者：
Berret.;Meissner;Watson;Pohl;Courtens
Low-temperature thermal conductivity and time-dependent specific heat have been measured on mixed crystals of ${\mathrm{Rb}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$(${\mathrm{NH}}_{4}$${)}_{\mathit{z}}$${\mathrm{H}}_{2}$${\mathrm{PO}}_{4}$ (x=0.35,0.72), in the composition range in which an electric dipole glass state forms below \ensuremath{\sim}100 K. Glasslike excitations have been observed. In the fully deuterated isomorph with x=0.62, however, the thermal conductivity is that of a crystal, and glasslike excitations are only seen in the specific heat at very long times. This striking isotope effect shows that the low-energy excitations in these crystals relate to tunneling of protons or deuterons, respectively.
Low-temperature thermal conductivity and time-dependent specific heat have been measured on mixed crystals of ${\mathrm{Rb}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$(${\mathrm{NH}}_{4}$${)}_{\mathit{z}}$${\mathrm{H}}_{2}$${\mathrm{PO}}_{4}$ (x=0.35,0.72), in the composition range in which an electric dipole glass state forms below \ensuremath{\sim}100 K. Glasslike excitations have been observed. In the fully deuterated isomorph with x=0.62, however, the thermal conductivity is that of a crystal, and glasslike excitations are only seen in the specific heat at very long times. This striking isotope effect shows that the low-energy excitations in these crystals relate to tunneling of protons or deuterons, respectively.