Neutron Diffraction Studies of single crystal Co-doped CeCu2Ge2

A systematic study of physical properties on Ce(Cu_{1-x}Co_x)_2Ge_2 reveals that the AFM ground state of CeCu2Ge2 can be continuously suppressed by Co doping and NFL type of behavior is seen around the critical concentration x_c ∼ 0.6. The TN vs x phase diagram shows two distinct regimes [Fig. 1(a)] that might be related to two different kinds of magnetic ordering T_N1 and T_N2. This result is very similar to the high-pressure experiment on pure CeCu2Ge2 where two different magnetically ordered phases are observed in different pressure ranges followed by a superconducting phase. We presumed that the different slopes of T_N vs x in different concentrations range are due to the different kinds of magnetic ordering, which requires further confirmation. We, therefore, propose to carry out elastic powder neutron diffraction studies on the single-crystalline sample of 5% Co-doped CeCu2Ge2.