Single crystal growth of Yb(Rh1-xNix)Si2: influence of chemical pressure and electron doping

YbRh2Si2 is a well-known heavy fermion compound, which has been investigated intensively due to proximity to an antiferromagnetic field induced quantum critical point (QCP). Recent experimental and theoretical investigations propose that this system displays an unconventional QCP driven by localized moments. We report details of the single crystal growth and physical properties of non-isovalent partial substitution of Rh by Ni. We have grown single crystals of Yb(Rh1-xNix)Si2 for x=0 to 1 using an Indium-flux method in an oxide crucible. The structure of the single crystals and their composition were investigated by X-ray-diffraction and microprobe analysis, respectively. We will report resistivity, specific heat and magnetic susceptibility measurements for various doping concentrations. Ni substitution has a twofold effect: chemical pressure and doping with electrons. By comparison with isovalent Co substitution and Fe-(hole)-doping, conclusions concerning the influence of chemical pressure and the change in carrier concentration are drawn.