Magnetic Field Effects in the Heavy Fermion Ce$_{3}$Co$_{4}$Sn$_{13}$

Ce$_{3}$Co$_{4}$Sn$_{13}$ is a heavy Fermion system with a low temperature specific heat as large as 4 J/mol K$^{2}$. Measurements on single crystal specimens of the elastic neutron scattering response and the heat capacity (C) show that Ce$_{3}$Co$_{4}$Sn$_{13}$ is extremely sensitive to applied magnetic fields. The heat capacity measurements show that the broad peak in C/T at 0.8 K at zero field initially moves downward in temperature before moving upward with a characteristic energy scale of 2 T. Neutron diffraction measurements at 0.15 K show that upon application of very small magnetic fields, the intensity on the (100) peak grows and does not saturate below 6 T. Although reduced in magnitude the effect persists to temperatures at least as high at 2 K.