MAGNETIC-PROPERTIES IN INTERMETALLIC COMPOUNDS DYMN2(SI1-XGEX)2 (0-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-1)

Magnetic measurements have been performed in order to investigate magnetic properties of pseudo-ternary compounds DyMn2(Si1-xGex), (0 less-than-or-equal-to x less-than-or-equal-to 1). As x increases, lattice parameters increase from a = 3.904 angstrom and c = 10.41 angstrom at x = 0 to a = 3.975 angstrom and c = 10.79 angstrom at x = 1, and the Neel temperature decreases from 523 to 430 K. In all the compounds, magnetic transitions are observed at low temperatures where Dy moments start to order magnetically. DyMn2Si2 has three magnetic phases below 38 K whose magnetic structures are long-periodic, and it is supposed that there occurs a magnetic short-range order of Dy moments between 38 and 83 K. The compounds with 0.1 less-than-or-equal-to x less-than-or-equal-to 0.6 have a magnetic phase below about 25 K with a canted-ferrimagnetic structure. This phase exists up to x = 0.9, although DyMn2Ge2 has a collinear-ferrimagnetic phase. For 0.7 less-than-or-equal-to x less-than-or-equal-to 1.0, there exists an intermediate-temperature phase which may have a ferrimagnetic structure with a long-periodic arrangement.