Abstract: A thin-film magnetic field sensor is provided which includes two arms of a bridge circuit formed of a first element having a giant-magneto-resistant thin-film, and soft magnetic thin-films disposed one on either side thereof, with electrical terminals, and a second element having a giant-magneto-resistant thin-film, and conductive films disposed one on either side thereof, with electrical terminals. The electrical resistance value of the second element has sensitivity relative to the magnetic field, such that it is substantially zero when the magnetic field is small, but it changes equally to the first element due to causes other than the magnetic field. Since the output of the bridge circuit is in proportion to the difference in electrical resistance values between the first and second elements, part of a change due to causes other than the magnetic field is canceled in the output of the bridge circuit, whereby the magnetic field value can be accurately measured.

Abstract: There is provided a thin-film magnetic field sensor, which has a simple structure and a high detecting sensitivity, and reduces measurement errors due to temperature variation or the like. In the thin-film magnetic field sensor according to the present invention, two arms of a bridge circuit are formed of an element 5 having a giant-magneto-resistant thin-film, and soft magnetic thin-films disposed one on either side thereof, with electrical terminals, and an element 10 having a giant-magneto-resistant thin-film, and conductive films disposed one on either side thereof, with electrical terminals. The electrical resistance value of the element 10 has sensitivity relative to the magnetic field, such that it is substantially zero when the magnetic field is small, but it changes equally to the element 5 due to causes other than the magnetic field.

Abstract: A perpendicular magnetic recording medium is formed of a substrate having 5.times.10.sup.5 -5.times.10.sup.9 fine projections per mm.sup.2 on the surface thereof, said projections having heights in the range of 0.01-10 .mu.m and diameters in the range of 0.01-1 .mu.m, and a ferromagnetic material deposited uniformly in a columnar form on the projections. The recording medium is produced by providing in advance fine projections, the heights and diameters of which are 0.01-10 .mu.m and 0.01-1 .mu.m respectively, on the surface of a substrate to a density of 5.times.10.sup.5 -5.times.10.sup.9 projections per mm.sup.2, and then causing a ferromagnetic material to deposit on the substrate from a vapor phase in such a way that the deposited material is preferentially allowed to adhere onto the projections and then to grow the ferromagnetic material in a direction perpendicular to the plane of the substrate.

Abstract: A method of producing fine particles with a particle size of submicron or finer which comprises the steps of:forming closely fine projections on a substrate surface, preferably by sputter-etching using an ionized gas; and thensputtering metallic or non-metallic materials onto the thus treated substrate in an inert gas or a mixed gas of an inert gas and a reactive gas, such as oxygen, the gas pressure of the inert gas or the mixed gas being in the range of from 1.times.10.sup.-4 torr to 1.times.10.sup.-1 torr, and thereby depositing the purposed fine particles in crystalline or amorphous form. The invention method can successfully provide fine particles with desired properties, for example, in size, shape and structure, by adjusting producing conditions or selection of substrate materials and the thus obtained fine particles are very useful in various applications with or without the substrate.