A magnetic head for reading information from and writing information to a
hard magnetic disk having reduced thermal protrusion at the air bearing
surface. In some embodiments, a read-head portion of the magnetic head
includes one or more read insulation layers, and a write-head portion of
the magnetic head includes one or more write insulation layers. The
magnetic head may optionally further include one or more insulation
layers between the read-head portion and the write-head portion. One or
more of these insulation layers includes a material with a negative
thermal expansion characteristic, including but not limited to, carbon
fiber, zirconium tungstate (Zr W.sub.2 O.sub.8), or hafnium tungstate (Hf
W.sub.2 O.sub.8).