Magnetic Transitions and Magnetoresistance of Y_1-xDy_xMn₆Sn₆ ( x = 0.2 and 0.3)

Magnetic transitions and magnetoresistance of HfFe₆Ge₆-type Y_1-xDy_xMn₆Sn₆ ( x = 0.2 and 0.3) have been investigated in the temperature range of 5-380 K. It was found that the strong exchange interaction between the Dy and Mn sublattices results in incomplete ferrimagnetism at low temperatures. At higher temperatures, the metamagnetic transition from an antiferromagnetic state to a ferrimagnetic state can be induced by a fairly small threshold field or by increasing temperature. The magnetic transition is accompanied by a large magnetoresistance effect of about -29% and -16% at 5 K for x = 0.2 and 0.3, respectively.