%0 Journal Article
%A Pecanha Antonio, Viviane
%A Feng, Erxi
%A Su, Yixi
%A Pomjakushin, Vladimir
%A Demmel, Franz
%A Chang, Lieh-Jeng
%A Aldus, Robert
%A Xiao, Yinguo
%A Lees, Martin R.
%A Brückel, Thomas
%T Magnetic excitations in the ground state of Yb$_{2}$ Ti$_{2}$ O$_{7}$
%J Physical review / B
%V 96
%N 21
%@ 2469-9950
%C Woodbury, NY
%I Inst.
%M FZJ-2017-08258
%P 214415
%D 2017
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000417635700002
%R 10.1103/PhysRevB.96.214415
%U https://juser.fz-juelich.de/record/841162