Magnetic order in Tm2Si2O7

We propose to probe the magnetic ground state of Tm2Si2O7 with neutron diffraction. The compound belongs to a family of rare-earth disilicates, whose magnetic properties remain largely unknown. Tm2Si2O7 has a monoclinic structure (C type), identical to the one found in Yb2Si2O7, where highly unusual low-T magnetic phase diagram has recently been reported. Our heat capacity measurements suggest that Tm2Si2O7 remains magnetically disordered down to at least 0.4 K, we therefore need a dilution refrigerator to reach sub 1 K temperatures.