Jeol Ltd.

Mitsubishi Gas Chemical Company, Inc.

Takeshi Tomita

Shoji Kato

Hiromitsu Nagashima

Yukio Ishiuchi

Michiya Kawakami

Atsushi Kimura

Yasushi Hiramatsu

Toshikazu Honda

Kimio Ohi

Yoshiyasu Harada

Masaki Takeguchi

Yu Ishibashi

A magnetic domain imaging system is offered which permits application of a strong magnetic field to a specimen. The imaging system includes a transmission electron microscope having an objective lens. The specimen that is magnetic in nature is placed in the upper polepiece of the objective lens. An electron beam transmitted through the specimen is imaged and displayed on a display device. A field application coil assembly for applying a magnetic field to the specimen and two deflection coil assemblies for bringing the beam deflected by the field applied to the specimen back to the optical axis are mounted in the upper polepiece.

Magnetic domain imaging system

An electron microscope equipped with an electron biprism is provided with second and third objective lenses placed between a sample and the electron biprism such that the sample is not affected by the magnetic fields produced by the objective lenses. The magnification of a TEM image of the sample at the focal point H is controllably varied by appropriately controlling the excitations of the objective lenses. The spacing of carrier fringes is adjusted by controllably varying the voltage applied to a line electrode of the biprism.

Electron microscope equipped with electron biprism

There is disclosed an electron-beam biprism for use in an electron-beam holographic interference microscope. The biprism comprises a rotary plate having a hole permitting passage of an electron beam, a biprism wire mounted to the rotary plate and electrically insulated from the rotary plate, a holder, a rotating mechanism, a heating mechanism for heating the biprism wire, a voltage source for applying a voltage to the biprism wire, and a pair of grounding electrodes extending parallel to the biprism wire which bridges across the hole. The rotary plate is rotatably held by the holder so as to be rotatable about the hole. The grounding electrodes are mounted to the rotary plate. The biprism wire is sandwiched between the grounding electrodes.

Electron-beam biprism

There is disclosed an apparatus for generating an electron beam in an electron microscope comprising an electron gun, a second anode located under the gun, an aperture plate having an aperture for limiting the electron beam, and a scattered electron-blocking member for limiting passage of the beam. The aperture plate is mounted in the beam passage formed in the second anode. The scattered electron-blocking member is located under the aperture plate. Electrons scattered at the edges of the aperture are blocked by the scattered electron-blocking member from colliding against the accelerator tube.

Electron beam-generating apparatus

This invention provides a process for producing hydrogen peroxide through catalytic reaction of oxygen with hydrogen in an aqueous medium in the presence of a platinum group metal catalyst, in which an organic solvent having only limited solubility with water and less hydrogen peroxide-dissolving ability compared to that of water is caused to be concurrently present in the reactor, and oxygen and hydrogen are catalytically reacted in an aqueous medium in the presence of a water- and organic solvent-insoluble, hydrophilic platinum group metal catalyst, under a low reaction pressure, to form high concentration aqueous hydrogen peroxide solution within a short time.

Process for producing hydrogen peroxide

The present invention provides a process for producing hydrogen peroxide by reacting oxygen and hydrogen in a reaction medium catalytically using, as a catalyst, a tin-modified platinum group metal supported on a carrier. In the process using said catalyst, the presence of halogen and acid in reaction medium is unnecessary unlike the prior art methods, and hydrogen peroxide of high concentration can be produced efficiently. Thus, the present process has no restriction for reactor material as seen the prior art methods and further allows for easy purification of produced hydrogen peroxide.

In a conventional electron beam-producing apparatus, a field emission gun is combined with an accelerating tube. An electrostatic lens focuses the electron beam diverging from the emitter. This conventional apparatus needs a large power supply for applying potentials to the electrodes of the lens and to the accelerating electrodes. Also, it is difficult to make stationary the position at which the crossover point of the electron beam is imaged. The present invention makes use of voltage-dividing resistors to produce fractions of the accelerating voltage. These fractions of the voltage are applied to the electrodes of the electrostatic lens and to various electrodes. This permits the use of a power supply that is smaller in size than conventional. The number of the used voltage-dividing resistors is increased or decreased, depending on the accelerating voltage. This makes it possible to fix the position of the crossover point imaged by the electrostatic lens.

Apparatus for producing and accelerating an electron beam

An electron microscope having plural stages of focusing lenses between an objective lens and an electron gun. The magnetic pole piece of the focusing lens of the final stage which is on the side of the objective lens takes a conic form which tapers toward the objective lens. The yoke of the objective lens on the side of the focusing lenses is centrally provided with a conic recess. This structure makes it possible to shorten the distance between the position of the magnetic field produced by an auxiliary lens and the front focal point defined by a front objective lens without introducing interference between the focusing lens of the final stage and the object lens proper. Thus, the observation of an electron micrograph covering a wide field of view facilitates accurate analysis of the physical properties of a designated microscopic region on a specimen.

Transmission-type electron microscope

When a transmission-type electron microscope is used to make an observation of a diffraction image produced by a focused electron beam, it is desired that the divergence angle of the electron beam be varied at will while maintaining the spot diameter of the beam on a specimen constant. The present invention provides three stages of focusing lenses and a means for controlling these lenses in interrelated manner in a space between an objective lens and an electron gun in which the specimen is placed. The three stages of lenses are designed to be controlled independently. When an operation is performed to increase the divergence angle of the electron beam, the excitations of the first and second stages of focusing lenses are reduced while the excitation of the third stage of focusing lens is increased, thus maintaining the spot diameter of the beam on the specimen constant.

Growing community of inventors

Tokyo, Japan

Takeshi Tomita