A quest for frustration driven distortion in Y2Mo2O7
  We investigated the nature of the freezing in the geometrically frustrated Heisenberg spin-glass Y2Mo2O7 by measuring the temperature dependence of the static internal magnetic field distribution above the spin-glass temperature, Tg, using the muSR technique. The evolution of the field distribution cannot be explained by changes in the spin susceptibility alone and suggests a lattice deformation. This possibility is addressed by numerical simulations of the Heisenberg Hamiltonian with magneto-elastic coupling at T>0. 
Eva Sagi, Oren Ofer, Amit Keren, and Jason S. Gardner