TY  - JOUR
AU  - Alekseev, P.A.
AU  - Mignot, J.-M.
AU  - Nemkovski, K.S.
AU  - Rybina, A.V.
AU  - Lazukov, V.N.
AU  - Ivanov, A.S.
AU  - Iga, F.
AU  - Takabatake, T.
TI  - Interplay of low-energy phonons and magnetiv excitations in the Kondo insulator YbB12
JO  - Journal of physics / Condensed matter
VL  - 24
SN  - 0953-8984
CY  - Bristol
PB  - IOP Publ.
M1  - PreJuSER-20759
SP  - 205601
PY  - 2012
N1  - 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.
AB  - 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.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:22510752
UR  - <Go to ISI:>//WOS:000303507100010
DO  - DOI:10.1088/0953-8984/24/20/205601
UR  - https://juser.fz-juelich.de/record/20759
ER  -