Structure and magnetic properties of RIn2.9Co0.1 (R=La, Ce, Pr, Nd)

The RIn₃ intermetallic compounds have received much attentions due to their interesting properties such as various magnetic structures, crystal field effects or heavy fermion behavior[1,2]. It is known that RIn₃ compounds crystallize in a cubic AuCu₃ type structure with a space group of Pm-3m. R and In atoms occupy 1a and 3c crystal positions. Most of those compounds undergo an antiferromagnetic phase transition (AFM) at low temperatures. Celn₃ is a well known Kondo-lattice compound showing antiferromagnetic ordering at 10K[3]. PrIn₃ shows Van Vleck paramagnetic characteristics in wide temperature regime, and antiferromagnetic nuclear ordering at extremely low temperature(0.14mK)[4]. NdIn₃ becomes antiferromagnetic below 5.9 K[5]. LaIn₃ represents one of the non-magnetic members in the family of the RIn₃ compounds. The superconduction transition temperature is 0.71K[6]. In this study, RIn_2.9Co_0.1 (R=La, Ce, Pr, Nd) compounds have been prepared by arc melting, and the doping effects of the 3d transition metal Co on crystal structure and magnetic properties have been investigated systemically by using X-ray diffraction and magnetic susceptibility measurements .