An inductive transducer has inorganic nonferromagnetic material disposed in
an apex region adjacent to a submicron nonferromagnetic gap in a magnetic
core. The inorganic nonferromagnetic material has a much lower coefficient
of thermal expansion than that of hardbaked photoresist, reducing pole tip
protrusion even if other insulation surrounding the coil sections within
the core is made of hardbaked photoresist. Alternatively, the entire
insulation surrounding the coil sections within the core, in addition to
the apex region, can be formed of inorganic nonferromagnetic material,
further reducing pole tip protrusion. The transducer has SiO.sub.2 rather
than alumina in an undercoat layer joining the wafer substrate and the
thin film layers of the transducer. SiO.sub.2 may also replace alumina in
other areas, such as a piggyback layer joining the inductive transducer
with a magnetoresistive transducer.
