TY - JOUR
T1 - Motion of the guest ion as precursor to the first-order phase transition in the cage system GdB 6
AU - Iwasa, Kazuaki
AU - Igarashi, Ryosuke
AU - Saito, Kotaro
AU - Laulhé, Claire
AU - Orihara, Toshihiko
AU - Kunii, Satoru
AU - Kuwahara, Keitaro
AU - Nakao, Hironori
AU - Murakami, Youichi
AU - Iga, Fumitoshi
AU - Sera, Masafumi
AU - Tsutsui, Satoshi
AU - Uchiyama, Hiroshi
AU - Baron, Alfred Q.R.
PY - 2011/12/28
Y1 - 2011/12/28
N2 - The motion of guest Gd ions in oversized boron cages in GdB 6 was investigated from phonon spectra measurements obtained by inelastic x-ray scattering. The measured phonon modes soften by about 10% from 300 K down to T N=16 K, in particular, the longitudinal phonon for the propagation vector q 1=(1/2,0,0) that characterizes the distorted structure below T N. Besides, the dispersion relation curves show kinklike anomalies at q k=(0.38,0.38,0). The observed results imply that the motion of the guest Gd ion interplays with the f electrons magnetoelastically and with carriers via Fermi surface nesting. The anomalous properties previously reported for this material far above T N originate from the strong electron-phonon coupling, which causes the motion of guest ions as precursors to the first-order phase transition.
AB - The motion of guest Gd ions in oversized boron cages in GdB 6 was investigated from phonon spectra measurements obtained by inelastic x-ray scattering. The measured phonon modes soften by about 10% from 300 K down to T N=16 K, in particular, the longitudinal phonon for the propagation vector q 1=(1/2,0,0) that characterizes the distorted structure below T N. Besides, the dispersion relation curves show kinklike anomalies at q k=(0.38,0.38,0). The observed results imply that the motion of the guest Gd ion interplays with the f electrons magnetoelastically and with carriers via Fermi surface nesting. The anomalous properties previously reported for this material far above T N originate from the strong electron-phonon coupling, which causes the motion of guest ions as precursors to the first-order phase transition.
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U2 - 10.1103/PhysRevB.84.214308
DO - 10.1103/PhysRevB.84.214308
M3 - Article
AN - SCOPUS:84855323106
VL - 84
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 21
M1 - 214308
ER -