%0 Journal Article
%A Alekseev, P.A.
%A Mignot, J.-M.
%A Nemkovski, K.S.
%A Rybina, A.V.
%A Lazukov, V.N.
%A Ivanov, A.S.
%A Iga, F.
%A Takabatake, T.
%T Interplay of low-energy phonons and magnetiv excitations in the Kondo insulator YbB12
%J Journal of physics / Condensed matter
%V 24
%@ 0953-8984
%C Bristol
%I IOP Publ.
%M PreJuSER-20759
%P 205601
%D 2012
%Z We are grateful to D Reznik for fruitful discussions and to the LLB and ILL for hospitality during the experiments. Financial support from RFBR grants 08-02-00430 and 11-02-00121 is highly appreciated.
%X Peculiarities in the lattice dynamics of the Kondo insulator Y bB(12) have been studied by inelastic neutron scattering. Selected phonon modes were traced above and below the temperature region (T ~ 50 K) where the gap opens in the electron density of states. The intensities of some low-energy modes exhibit an anomalous temperature dependence for q vectors close to the Brillouin zone boundary, suggesting a renormalization of the phonon eigenvectors. This effect is thought to arise from a coupling with magnetic excitations of the same symmetry, which exist at nearby energies. It is argued that this magnetovibrational coupling may in turn play a role in the steep temperature crossover existing in Y bB(12) between the low-temperature (Kondo insulator) and high-temperature (incoherent spin-fluctuation) regimes, which is rapidly suppressed by lighter Zr substitution.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:22510752
%U <Go to ISI:>//WOS:000303507100010
%R 10.1088/0953-8984/24/20/205601
%U https://juser.fz-juelich.de/record/20759