Effects of Co substitution on structural and magnetic properties of R3(Fe1−xCox)29−yVy (R=Tb, Dy)

Abstract Synthesis of two novel series of intermetallic compounds Tb 3 (Fe 1− x Co x ) 27.4 V 1.6 ( x =0,0.1, 0.2, 0.3, 0.4) and Dy 3 (Fe 1− x Co x ) 27.8 V 1.2 ( x =0, 0.1, 0.2, 0.3) with the monoclinic Nd 3 (Fe,Ti) 29 -type structure (3:29) is presented. In the Dy series for x =0.4 a disordered variant of the hexagonal Th 2 Ni 17 -type structure is formed. The cell parameters decrease and the Curie temperature increases with increasing of the Co content. In the case of the Tb 3 (Fe 1− x Co x ) 27.4 V 1.6 series in the M ( T ) curve a magnetic transition is observed which is attributed to spin reorientation phenomena. This critical temperature decreases with increasing Co from 473 K for x =0.1 to 393 K for x =0.3, and was not observed in the case of 0.4. XRD patterns of magnetically aligned powder samples reveal the presence of a tilted magnetic structure.