TY  - JOUR
AU  - Pecanha Antonio, Viviane
AU  - Feng, Erxi
AU  - Su, Yixi
AU  - Pomjakushin, Vladimir
AU  - Demmel, Franz
AU  - Chang, Lieh-Jeng
AU  - Aldus, Robert
AU  - Xiao, Yinguo
AU  - Lees, Martin R.
AU  - Brückel, Thomas
TI  - Magnetic excitations in the ground state of Yb$_{2}$ Ti$_{2}$ O$_{7}$
JO  - Physical review / B
VL  - 96
IS  - 21
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-08258
SP  - 214415
PY  - 2017
AB  - We report an extensive study on the zero field ground state of a powder sample of the pyrochlore Yb$_{2}$Ti$_{2}$O$_{7}$. A sharp heat capacity anomaly that labels a low temperature phase transition in this material is observed at 280 mK. Neutron diffraction shows that a quasicollinear ferromagnetic order develops below Tc with a magnetic moment of 0.87(2)μB. High resolution inelastic neutron scattering measurements show, below the phase transition temperature, sharp gapped low-lying magnetic excitations coexisting with a remnant quasielastic contribution likely associated with persistent spin fluctuations. Moreover, a broad inelastic continuum of excitations at ∼0.6 meV is observed from the lowest measured temperature up to at least 2.5 K. At 10 K, the continuum has vanished and a broad quasielastic conventional paramagnetic scattering takes place at the observed energy range. Finally, we show that the exchange parameters obtained within the framework of linear spin-wave theory do not accurately describe the observed zero field inelastic neutron scattering data.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000417635700002
DO  - DOI:10.1103/PhysRevB.96.214415
UR  - https://juser.fz-juelich.de/record/841162
ER  -