Charge fluctuations and the valence transition in Yb under pressure.
نویسندگان
چکیده
We present a dynamical mean-field theory study of the valence transition (f;{14} --> f;{13}) in elemental, metallic Yb under pressure. Our calculations reproduce the observed valence transition as reflected in the volume dependence of the 4f occupation. The transition is advanced by heating, and suggests quasiparticle or Kondo-like structure in the spectra of the trivalent end state, consistent with the early lanthanides. Results for the local charge fluctuations and susceptibility, however, show novel signatures uniquely associated with the valence transition itself, indicating that Yb is a fluctuating valence material in contrast with the intermediate valence behavior seen in the early trivalent lanthanides Ce, Pr, and Nd.
منابع مشابه
Novel effect of critical valence fluctuations in unconventional superconductivity of Ce-based heavy fermions and related compounds
For this decade, our group has developed a theory for unconventional superconductivity in Ce-based heavy fermion systems CeCu2(Ge,Si)2 which exhibits anomalous enhancement of superconducting transition temperature Tsc and non-Fermi liquid properties such as T-linear resistivity and huge enhancement of residual resistivity under pressure P~Pv where the valence of Ce ion appears to change drastic...
متن کاملValence fluctuationmediated superconductivity inCeCu2Si2
It has been proposed that there are two types of superconductivity in CeCu2Si2, mediated by spin fluctuations at ambient pressure, and by critical valence fluctuations around a charge instability at a pressure Pv ≃ 4.5 GPa. We present in detail some of the unusual features of this novel type of superconducting state, including the coexistence of superconductivity and huge residual resistivity o...
متن کاملCrossover from a heavy fermion to intermediate valence state in noncentrosymmetric Yb2Ni12(P,As)7
We report measurements of the physical properties and electronic structure of the hexagonal compounds Yb2Ni12Pn7 (Pn = P, As) by measuring the electrical resistivity, magnetization, specific heat and partial fluorescence yield x-ray absorption spectroscopy (PFY-XAS). These demonstrate a crossover upon reducing the unit cell volume, from an intermediate valence state in Yb2Ni12As7 to a heavy-fer...
متن کاملStrong coupling between 4f valence instability and 3d ferromagnetism in Yb(x)Fe4Sb12 studied by resonant x-ray emission spectroscopy.
We have investigated the temperature and pressure dependency of the electronic structure of Yb-filled skutterudites, YbFe(4)Sb(12) and Yb(0.88)Fe(4)Sb(12), using x-ray absorption and emission spectroscopies. An anomalous increase of the Yb valence, which is beyond the conventional Anderson model picture, is found to coincide with the onset of the ferromagnetic order in the x=0.88 sample below 2...
متن کاملPhase transitions in rare earth tellurides under pressure.
Using first-principles calculations we have studied the valence and structural transitions of the rare earth monotellurides RTe (R = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb) under pressure. The self-interaction corrected local spin-density approximation is used to establish the ground state valence configuration as a function of volume for the RTe in both the NaCl (B1) and CsCl (B...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 102 24 شماره
صفحات -
تاریخ انتشار 2009