The results of studies of the interaction of components in the following systems are presented: R2T2In1-xMx (R = La, Ce; T = Ni, Cu; M = Al, Ga, Sn, Sb, Bi), R2T2-xGexIn (R = La, Ce; Т = Ni, Cu), Gd2Cu2In1-xMx (M = Al, Ga, Si, Ge), RNi2Ge2-xInx (R = La, Ce, Pr), RNi2Si2-xInx (R = La, Ce), RCu1-xGaxIn (R = La, Ce), RPd1-xGexIn (R = La, Ce, Nd), RRh1-xGexIn (R = La, Nd) and CeCu1-xAgxIn at 870 K.
The phase composition of the obtained samples was established by means of X-ray phase analysis and, partially, scanning electron microscopy (EDX), and the crystal structures of the phases were determined by means of X-ray structural analysis. Based on the obtained results, the ranges of solubility of the fourth component in the initial compounds, the ranges of solid solutions and the change of unit cell parameters, and the effect of substitution on the structure and properties of the obtained compounds were determined. It was found that continuous solid solutions are not formed in any of the systems, but in 27 systems solid solutions with limited solubility exist, and they crystallize in Mo2FeB2, CaBe2Ge2, ZrNiAl, CaIn2 structure types. Solid solutions are not formed in 15 systems.
For the first time the existence of 30 quaternary and ternary compounds R7Ni5±xGe3±xIn6 (R = La, Ce, Pr, Nd, Sm, Gd) (Ce7Ni5Ge3In6-type structure), CePd0.71Ge0.29In, LaPd0.81Ge0.19In, PrPd0.73Ge0.27In, LaRh0.65Ge0.35In, CeRh0.71Ge0.29In, PrRh0.75Ge0.25In, NdRh0.70Ge0.30In, SmRh0.67Ge0.33In (ZrNiAl-type structure) and CeNiIn0.57Sn0.43 (ZrNiAl-type structure), Ce5Cu0.57In0.43Bi3 (Hf5CuSn3-type structure), CeNi3In5Sn (LaNi3In6-type structure), LaNi2Ge0.8In1.2, CeNi2GeIn, PrNi2Ge1.5In0.5 and CeNi2SiIn (CaBe2Ge2-type structure), LaCu0.4Ga0.6In and CeCu0.5Ga0.5In (CaIn2-type structure), Ce2Ni2In0.8Al0.2, Ce2Ni2In0.8Sn0.2 and Ce2Cu2In0.8Sn0.2 (Mo2FeB2-type structure), Nd39Ir10.98In36.02 (own structure type), NdAu0.55In1.45 (CaIn2-type structure), La5Ir1.73In4.27 (Lu5Ni2In4-type structure), Dy11Ge4.33In5.67 (Sm11Ge4In6-type structure), was determined. The crystal structure of 24 compounds was studied by the single crystal method. For the two known ternary compounds YbNiGe (TiNiSi-type structure) and Gd2Cu2In (Mo2FeB2-type structure) the crystal structure was solved by means of single crystal X-ray analysis.
Peculiarities of the component interaction in the studied systems were discussed. The structural transition of a solid solution with the ZrNiAl-type structure to a solid solution with the CaIn2-type structure in the RCu1-xGaxIn systems (R = La, Ce) and transition between the compounds with CeAl2Ga2-type structure (RNi2Ge2, RNi2Si2) and CaBe2Ge2-type structure (RNi2Ge2-xInx, RNi2Si2-xInx) were established.
Crystal chemical and topological analyzes have been performed for a number of new ternary and quaternary compounds and their relationships with known simple types of intermetallic compounds have been established.
For the Ce7Ni5Ge3In6 compound the study of magnetic properties was carried out, and for phases of CePd1-xGexIn solid solution magnetic and electric transport measurements were performed.
