Abstract: Vertical magnetic head with an integrated coil and its production process wherein the head comprises two pole pieces (30.sub.2, 30.sub.2) and two integrated coils 50.sub.1, 50.sub.2), which are interconnected by a conductor bridge (75). A magnetic or permeability bridge (70) connects the two pole pieces and closes the circuit.

Abstract: Process for producing red and/or write heads for magnetic recording.According to the invention, use is made of a monocrystalline substrate (16), which is anisotropically etched in accordance with a crystallographic plane in order to give the gap (48) its precise direction (straight or inclined). The substrate also undergoes thermal oxidation to give the gap a given thickness.Application to heads for video recording.

Abstract: Magnetic hexagonal ferrites, in which ferrites the iron atom may be optionally substituted (substituted or unsubstituted barium hexaferrites, etc.), are prepared in high yields, and under non-corrosive conditions by a hydrothermal synthesis reaction between at least one alkali metal ferrite and a compound which releases an alkaline-earth metal ion in water (baryta, etc.) and optionally one or more alkali metal salt(s) of metal oxides. Magnetic hexagonal ferrites can be used as materials for permanent magnets and for ultrahigh frequency components or for magnetic recording materials. For example, ferromagnetic particles having a specific magnetization of at least 65 emu/g and a coercive field strength of at least 2500 oersteds can be prepared.