Jikikogakukirokuzairyo

摘要

PURPOSE:To obtain a recording material having a large magnetic Kerr effect at a low Curie temp. by limiting the component compsn. of an amorphous alloy film consisting of Tb alone or a component contg. essentially Tb and constituted of Tb and other rare earth elements and Fe alone or a component constituted of other transition metals except Ni and Fe. CONSTITUTION:The composition formula of the essential component of an amorphous alloy film consisting essentially of Tb and Fe is of the numerical value in the range of 0.05=x=0.8, 0.1=y=0.4 when expressed by the formula I . The R in the formula I of the amorphous alloy forming such material is Tb alone or contains essentially Tb and is constituted of other rare earth elements. The other rare earth elements that can be added to the Tb to be used essentially for the same are preferably heavy rare earth elements such as Gd, Dy, Mo, Er, Tm, etc. The M in the formula I is Fe alone or is constituted of the other transition elements except Ni and Fe. The other transition element except Ni is most preferably Co in order to obtain a large magnetic Kerr rotating angle. The compsn. has the larger magnetic Kerr rotating angle although the Curie temp. is low. The smaller decrease in the temp. up to about the Curie point necessary for writing of a record is therefore required and since the amorphous alloy has no possibility of crystallizing non-reversibly, the repetitive use is made possible.