Pressure effect on some magnetic properties of the HfFe6Ge6-type ScMn6Sn5.45In0.55, YMn6Sn5.65In0.35 and LuMn6Sn5.1In0.9 compounds

Temperature and pressure dependence of magnetic properties of HfFe6Ge6-type ScMn6Sn5.45In0.55. YMn6Sn5.65In0.55 and LuMn6Sn5.1In0.9 compounds are reported. The three compounds are characterized by similar magnetic properties. At ambient pressure, they order ferromagnetically about the room temperature (293 less than or equal to T-c less than or equal to 356 K) and undergo a ferro to helimagnetic transition upon cooling (235 less than or equal to T-i less than or equal to 327 K). The external pressure acts in the same way for all three compounds. The increase of pressure yields a linear increase of T-c and a decrease of T-i The present results are discussed and compared with the corresponding properties of the isotypic compounds RMn6Ge6-xGax (R = Sc. Y. Lu). (C) 2004 Elsevier B.V. All rights reserved.