Uniaxial pressure dependencies of the phase boundary of TlCuCl_3
  We present a thermal expansion and magnetostriction study of TlCuCl_3, which shows a magnetic-field induced transition from a spin gap phase to a Neel ordered phase. Using Ehrenfest relations we derive huge and strongly anisotropic uniaxial pressure dependencies of the respective phase boundary, e.g. the transition field changes by about $\pm 185$ GPa depending on the direction of uniaxial pressure. 
N. Johannsen, A. Oosawa, H. Tanaka, A. Vasiliev, and T. Lorenz