Lack of static lattice distortion in $Tb_2 Ti_2 O_7$
  We investigated the possibility of temperature dependent lattice distortions in the pyrochlore compound Tb$_{2}$Ti$_{2}$O$_{7}$ by measuring the internal magnetic field distribution, using muon spin resonance, and comparing it to the susceptibility. The measurements are done at temperatures as low as 70 mK and external fields up to 6 kG. We find that the evolution of the width of the field distribution can be explained by spin susceptibility only, thus ruling out a temperature dependent hyperfine coupling. We conclude that lattice deformations are absent in Tb$_{2}$Ti$_{2}$O$_{7}$. 
Oren Ofer, Amit Keren, Chris Baines and Jason S. Gardner