A study of the La1-xYxMnSi (0≤x≤0.8) solid solution by magnetization and neutron diffraction measurements

Magnetization measurements and neutron diffraction study have been performed on the CeFeSi-type La1-xYxMnSi solid solution (0 less than or equal to x less than or equal to 0.8). The lanthanum-rich compounds (x<0.2) are characterized by antiferromagnetic Mn (001) planes and the yttrium-rich compounds (x greater than or equal to 0.8) by ferromagnetic Mn planes. The compounds of intermediate compositions (0.4 less than or equal to x less than or equal to 0.6) order antiferromagnetically and display a second magnetic transition at lower temperature, yielding the formation of canted planes where both ferro- and antiferromagnetic components coexist. These magnetic behaviours are discussed and compared with those of isotypic ternary RMnSi and of related ThCr2Si2-type compounds. (C) 1998 Elsevier Science S.A.