Abstract: A thin-film magnetic head has a slider formed of nonmagnetic polycrystalline Mn--Zn ferrite containing from 0.02 to 7 wt % of at least one member selected from the group consisting of CaO, MgO, ZrO.sub.2, SnO.sub.2, Al.sub.2 O.sub.3, SrO and NiO. Concave-convex surface having height difference is given to air bearings on a floatation surface side of the slider so that the convex portions occupy the area percentage in a range of from 20 to 80%.

Abstract: A non-magnetic substrate material which contains 0.5%-3% of Al.sub.2 O.sub.3 and 3%-16% of at least either ZnO or SnO.sub.2 (but with ZnO+SnO.sub.2 <=16%) in addition to components of 45%-60% of TiO.sub.2, 5%-20% of BaO and 20%-35% of CaO, and a floating-type magnetic head with a slider made of the above-mentioned non-magnetic substrate material.

Abstract: The object of the present invention is to provide a small-sized photographic material processing unit of a simple structure capable of developing both disk film and roll film simultaneously or selectively. In order to attain this object, the present invention is characterized in that in the photographic material processing unit adopted to process the photographic material by allowing it pass through a processing tank containing a processing solution, the disk film and/or foll film are passed through the same processing tank while they are held by a carrier.