{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$extrm{Mn}_{1-x} extrm{Ge}_x extrm{Bi}_2 extrm{Te}_4$$\\end{document}have been carried out with gradual replacement of magnetic Mn atoms by non-magnetic Ge atoms when concentration of the latter was varied from...