Single crystal growth and electronic state of new compounds RPt2Cd20 ( R = La-Nd, Sm)

We succeeded in growing five new single crystalline compounds RPt2Cd20 (R = La, Ce, Pr, Nd, and Sm) by the Cd self-flux method. These compounds are found to crystallize in the cubic CeCr2Al20-type crystal structure by the X-ray diffraction using single crystals. We measured the electrical resistivity, magnetic properties, and specific heat for all compounds. The resistivity for R = Ce, Nd, and Sm indicates an abrupt decrease, which might correspond to a magnetic transition. It is suggested that the ground state of CePt2Cd20 is Gamma(7) doublet from the magnetization measurement. The magnetization of PrPt2Cd20 shows a metamagnetic behavior at 1.6 T in the paramagnetic state, which could be due to the crystalline electric field effect with non-Kramers Gamma(3) doublet or Gamma(1) singlet ground state. The contribution of optical phonon modes to the lattice specific heat is discussed in LaPt2Cd20. (C) 2016 Elsevier B. V. All rights reserved.