Magnetic head

A magnetic head comprising a pair of core halves, said core halves being joined at magnetic-gap forming faces of said core halves so as to form a magnetic gap, each of said magnetic-gap forming faces having an area of not more than 300 .mu.m.sup.2, at least gap-forming portions of said core halves being made of a single-crystal ferrite, each of said core halves comprising track-width defining faces on both sides of said magnetic-gap forming face, said core halves being joined by a joining material filling regions formed by said track-width defining faces,

• wherein said magnetic-gap forming faces are in the (100) plane of said single-crystal ferrite;
• the magnetic circuit direction perpendicular to said magnetic-gap forming faces is in the <100>
• direction;
• the magnetostriction .lambda.<100>
• of said core halves in said <100>
• direction is negative;
• a tensile stress in said <100>
• direction caused by the difference in the coefficients of thermal expansion between said joining material and said single-crystal ferrite is applied to said gap-forming portions of said core halves;
• the absolute value of the magnetostriction constant of said core halves in said <100>
• direction is not more than 7.times.10.sup.-6 ;
• the ratio of the average coefficient of thermal expansion of said joining material to that of said single-crystal ferrite is in a range of from 0.85 to 1 at 100.degree. C. to 300.degree. C.;
• and said single-crystal ferrite is composed of 51.5 to 54.5 mol % of Fe.sub.2 O.sub.3, 23 to 26.5 mol % of MnO, and 21 to 23.5 mol % of ZnO.