Magnetic analysis of an Antarctic mesosiderite, ALH-77219

Abstract

Magnetic analyses are made on an Antarctic mesosiderite ALH-77219,and chemical analyses of metallic grains in the mesosiderite are carried out with the aid of an EPMA. The EPMA analyses show that the metallic phases in ALH-77219 are composed of kamacite of 5-6wt% Ni and taenite of about 50wt% Ni. The thermomagnetic analyses show that the mesosiderite ALH-77219 contains kamacite phase of about 6wt% Ni on average of 19.3% in weight and taenite phase of about 54wt% Ni on average of 6.3% in weight. The major parts of the taenite phase are of the superlattice structure of tetrataenite, which has a large magnetic anisotropy.