the pole pieces being ferrite

Full Title

Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor (G11B11/00 take precedence) > Structure or manufacture of heads, e.g. inductive > Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features (G11B5/265, , G11B5/31 take precedence) > the pole pieces being ferrite