As a magnetic material, ferrite has been broadly used in various fields described below.
Ferrite has been popularly used in various applications. For example, ferrite has been used as hard ferrite in a miniaturized motor-use magnetic pole which makes use of a rotor-use magnet, a measuring device, an electric device such as a microphone or a speaker, a magnet roller, a magnetic separator, a machine mechanism such as a magnetic bearing, a magnet in health promoting equipment, a magnet incorporated in a stationery, a magnet incorporated in a toy and the like. Ferrite has been also used as soft ferrite in a magnetic core, a magnetic head or a magnetic shield for power transmission, communication, deflection of beams in a CRT or the like which makes use of soft magnetism; a microwave device which makes use of a microwave property such as a filter, an isolator, a circulator, an antenna or an electromagnetic wave absorber; an optical communication/optical device which makes use of a magneto-optical property such as an optical isolator, an optical circulator, a photo switch or a magnetic field sensor; a microwave communication device which makes use of a microwave property such as a filter, a resonator or a circulator; and a magnetic memory device such as a magnetic bubble memory.
In the above-mentioned respective applications, properties which ferrite is required to satisfy vary largely and hence, it is necessary to provide ferrite which has properties conforming to each application.
Magnetic properties of ferrite mainly depend on component composition of ferrite and hence, to provide ferrite having desired properties, it is necessary to adjust the composition of ferrite to the component composition which conforms to required properties.
Conventionally, to grasp a change in magnetic properties accompanying a change in composition of ferrite, a large number of ferrite specimens which are made slightly different from each other in component composition of ferrite are prepared, and the magnetic properties of the respective specimens are measured one by one (non-patent document 1, for example).
However, the preparation of even one specimen requires a large number of steps from the preparation of raw materials to the manufacture of a sintered body. Further, it is necessary to prepare a large number of such specimens in which the component composition is made slightly different from each other for every composition and hence, not only it takes a long time to prepare the specimens, but also a cost is pushed up. The related art also has a drawback that the accuracy of measurement is lowered due to disturbances described below during the preparation of specimens.
When samples are prepared and evaluated one by one, the biggest concern is whether or not the preparation and the evaluation can be carried out in the same environment. For example, when a series of experiments is carried out over several days, the possibility that the preparation and the evaluation of the samples are influenced by the weather such as the temperature and the humidity is increased. Further, as to other concerns, whether or not the Supply of electricity to a device is stable, whether or not the device interferes with a peripheral device and the like are named.
In this respect, if a large number of samples can be prepared and evaluated at the same time, the above-mentioned possibility could be remarkably lowered.