Magnetic state of Fe atoms in La(Fe1-xVx)(2)Si-2 (0 <= x <= 0.5) compounds

Magnetic properties of quasi-ternary La(Fe1-xVx)(2)Si-2 compounds were stud ied in the composition range (0 less than or equal to x less than or equal to 0.5) of existence of solid solutions. The LaFe2Si2 ternary compound is a Pauli paramagnet with a virtually temperature-independent magnetic suscept ibility. The V-containing compounds exhibit temperature dependence of the m agnetic susceptibility obeying the Curie-Weiss law with a negative paramagn etic Curie temperature (Theta(p) approximate to-9 to -21 K) and effective m agnetic moment mu(eff) equal to approximate to 0.51-2.48 mu(B)/f.u. It was assumed that, in contrast to the ternary compound, Fe atoms in the quasi-te rnary compounds (x > 0) have a magnetic moment. Measurements of the electri cal resistivity and thermal expansion and neutron diffraction analysis of t he La(Fe0.5V0.5)(2)Si-2 compound with the maximum effective magnetic moment shows that no long-range magnetic order is found above 4.2 K.