Showing papers in "Japanese Journal of Applied Physics in 1969"
1,665 citations
150 citations
TL;DR: In this article, the anisotropy of surface state density, Nss, 1/f-type equivalent noise voltaze, VN, and field effect mobilitv, µFE, in p-channel MOS transistors with various crystallographic orientations in and zones was investigated.
Abstract: Experimental results are reported concerning the anisotropy of surface state density, Nss, 1/f-type equivalent noise voltaze, VN, and field effect mobilitv, µFE, in p-channel MOS transistors with various crystallographic orientations in and zones. The amounts of VN and Nss are strongly correlated to each other, and both appear to be smallest around (811)-oriented surfaces. µFE under strong electric field normal to the surface shows no apparent correlation to Nss, but is markedly dependent on the direction of current flow on each surface except (111) and (100): µFE is maximum in the direction parallel to [01] on (011) plane and µFE⊥[01] is higher than µFE//[01] on the planes between (111) and (100). The mobility anisotropy is interpreted in terms of the effective mass anisotropy caused by quantized hole motion, considering that the energy band structure at high energy remarkably differs from the one at lower energy.
109 citations
91 citations
TL;DR: In this article, a new orientation relationship consistent with the morphology is proposed, according to which the two halves divided by the plane of ridge can be regarded as variants of martensite as well as twins to each other.
Abstract: Thermoelastic γ' Cu–14.2A1–4.3Ni (w/o) martensite has been studied using the techniques of electron microscopy and electron diffraction, in order to explain the morphology on a microscopic scale. A plane of ridge which is frequently observed in a typical "spear-like" martensite has been identified as (121)γ' twinning plane. Further it has been shown that each half divided by the plane of ridge is internally twinned on {121}γ', other than the (121)γ' plane and each internal twin is faulted on each basal plane. A new orientation relationship consistent with the morphology is proposed, that is (110)[1]β1 //(121)[20]γ', according to which the two halves divided by the plane of ridge can be regarded as variants of martensite as well as twins to each other. This feature can be satisfied only by the new orientation relationship. Twinning nature of "spear-like" martensite is also discussed.
90 citations
TL;DR: In this paper, the growth rate of a tin whisker is proportional to the strain energy in parent material; does not depend on its thickness; and the maximum thickness of whiskers is in inverse proportion to the strained energy.
Abstract: Growing processes of tin whiskers out of the tin phase of Al–Sn alloy were investigated. The particular distribution of angular bends observed in kinked tin whiskers and the formation of kinks are explained by the following two assumptions: (1) The incoherent boundary between the tin whisker and the parent material of tin phase corresponds to the so-called coincidence site boundary, and (2) on this coincidence site boundary whiskers cause a boundary-slip on account of a stress unbalance occurring at the root of whiskers during growth. Meanwhile, the crystallization growth concept proposed by Ellis, et at. (1958) is modified, and thereby the growing process of whisker is discussed theoretically. It is concluded that the growth rate of whisker is proportional to the strain energy in parent material; does not depend on its thickness; and the maximum thickness of whiskers is in inverse proportion to the strained energy. These conclusions are in good agreement with the experimental results.
74 citations
TL;DR: In this article, the optical properties of thin electroformed metallic meshes were described in detail and two types of Fabry-Perot Interferometers (FPI's) for the far infrared were fabricated.
Abstract: This paper describes optical properties of thin electroformed metallic meshes in detail. Since the transmittance shows the bandpass character around the wavelength near the grid constant, metal mesh can be used as a bandpass filter. The reflectance is high in the wavelength region longer than three times the grid constant and the absorptivity is very low. These optical properties are suitable for reflectors of the Fabry-Perot Interferometers (FPI's) for the far infrared. Authors fabricated two types of FPI's; flxed type and tunable type. The absorption spectra of atmospheric water vapour between 100 and 400 µ and CO gas between 350 and 650 µ were scanned with the tunable FPI. Resultant resolving power of about 20 was obtained at 250 µ. Moreover, light flux which a FPI can utilize in the limited area of the light source and the detector was discussed.
74 citations
TL;DR: In this paper, it has been known that the transition temperature (Tc) of VO2 is shifted by doping specified elements in VO2 and experiments have been performed with adding various elements.
Abstract: It has been known that the transition temperature (Tc) of VO2 is shifted by doping specified elements in VO2. In order to shift Tc in still wider range, experiments have been performed with adding various elements. As a result, it has become possible to shift the Tc of VO2 either towards a higher temperature or towards a lower temperature. The doping elements which shift Tc towards a higher temperature are Ti and Ge. Those which shift it towards a lower temperature are Fe, Co, Ni, Mo, Nb, and W. In the research conducted, it has been able to vary the Tc within the range of 0–90°C. As for the relationship between the Tc and the lattice constant of the crystals, there exists a correlation with the cr of the tetragonal phase of VO2. Tc is nearly proportional to the quantity or cr: the more the cr, the higher true Tc is; the less the cr, the lower the Tc is.
67 citations
66 citations
TL;DR: In this paper, the temperature dependence of piezoelectric constants was discussed on the basis of the electrostrictive effect in the paraelectric phase biased by spontaneous polarization.
Abstract: Piezoelectric and elastic constants of lithium tantalate single crystal were measured from room temperature up to the Curie point (630°C). These constants were obtained by measuring resonant and antiresonant frequencies of bars and plates with various orientations. Temperature dependence of piezoelectric constants was discussed on the basis of the electrostrictive effect in the paraelectric phase biased by spontaneous polarization. Anomalous behavior of d33 and d31 was well explained by the dielectric anomaly of e33T.
58 citations
TL;DR: In this paper, a D-C reactive sputtering method with various sputtering voltages was used to prepare annealed CdO films for X-ray diffraction and reflection electron diffraction.
Abstract: CdO films were prepared by a D–C reactive sputtering method with various sputtering voltages. The characters of the prepared films are compared with the reflection electron diffraction and X-ray diffraction patterns. Especially, the effects of the sputtering voltage and partial pressure of oxygen were investigated concerning the electron densities and the Hall mobilities. The observations on lattice parameters lead to the conclusion that CdO films with high carrier concentrations contain some amount of interstitial excess Cd atoms. The absorption edge variation of annealed films prepared by high voltage sputtering agrees with the theoretical curve which is accounted from the Fermi level shift caused by the change in carrier concentrations.
TL;DR: In this article, the properties and the model of a CdS photovoltaic cell made by treating a ceramic plate electrochemically in copper ion solution were analyzed by means of X-ray Ginuie camera and X-Ray microanalyser.
Abstract: This paper describes the properties and the model of ceramic CdS photovoltaic cell made by treating CdS ceramic plate electrochemically in copper ion solution. The compositions and structures were analysed by means of X-ray Ginuie Camera and X-ray microanalyser. It was found that Cu2-xS (0x0.2) is formed along grain boundaries over a range of a several ten microns of the surface layer, and that the photovoltaic junctions exist at grain boundaries in this surface layer. From examinations of the voltage dependence of the barrier capacitance, the junctions could be classified into step junction, graded junction and Mott barrier, according to the prepared method. The spectral response measurement indicates that the origin of the photo-emf of the Mott barrier is mostly impurity photovoltaic effect.
TL;DR: In this paper, the etch rate of SiC crystals with hydrogen was investigated as a function of the reaction temperature, the hydrogen flow velocity and the hydrogen partial pressure in the H2-Ar mixture.
Abstract: The etch rate of SiC crystals with hydrogen was investigated as a function of the reaction temperature, the hydrogen flow velocity and the hydrogen partial pressure in the H2-Ar mixture. An etching reaction mechanism and calculated expressions for the etch rate have been developed based on thermodynamical considerations. The experimental results are well explained from the approximate expression at the etch rate region higher than about 3 µ/min.
TL;DR: The electrical conductivity and magnetic susceptibility of binary compounds CuxSe (x=2.0, 1.8 and 1.0) and CuxS (x =1.8, 1, 5, 0.5 and 0.8) were studied over the temperature range from -150°C to 150°C.
Abstract: The electrical conductivity and magnetic susceptibility of binary compounds CuxSe (x=2.0, 1.8, 1.5, 1.0 and 0.5) and CuxS (x=1.8 and 1.0) were studied over the temperature range from -150°C to 150°C. These compounds are near metallic conductors with resistivities of 100 to 6000µΩcm. It is found that Cu3Se2 may be antiferromagnetic, while the others are diamagnetic or weakly paramagnetic. A qualitative discussion is presented on the basis of the valencies of constituents and coordination configurations in order to explain the physical properties of these substances.
TL;DR: In this paper, Schottky barrier diodes were fabricated by vacuum depositions of Au, Ag, and Cu onto chemically cleaned silicon surfaces and their currentvoltage and capacitance-voltage characteristics were investigated in details over a temperature range between 100°K and 350°K.
Abstract: Schottky barrier diodes were fabricated by vacuum depositions of Au, Ag, and Cu onto chemically cleaned silicon surfaces and their current-voltage and capacitance-voltage characteristics were investigated in details over a temperature range between 100°K and 350°K. The current-voltage characteristics obtained are of nearly ideal Schottky barrier type and the current transport in the barriers is dominated by the thermionic emission and the image force effect. The temperature coefficient of the barrier height, the forward "n", and the image force dielectric constant were found to be (2.67±0.60)×10-4 eV/°K, 1.01~1.02, and 11.5e0 respectively. The departure from the ideal characteristics was explained by the generation-recombination current in the barrier region.
TL;DR: In this paper, the Ni-12 at. % Ti alloy was studied by means of thin foil transmission electron microscopy and electron diffraction technique, which showed two stage age-hardening at 500°C and 600°C.
Abstract: Precipitation behaviour in Ni-12 at. % Ti alloy was studied by means of thin foil transmission electron microscopy and electron diffraction technique. Hardness measurements showed two stage age-hardening at 500°C and 600°C. Thin foil observations revealed that the initial rapid increase in hardness was associated with the presence of superlattice. Slower second hardening was caused by the formation of modulated structure or periodic ordered structure. The increase in hardness by these periodic structures was found to be due to the internal strain hardening as originally suggested by Mott and Nabarro.
TL;DR: In this article, the acceptors are initially formed at the crystal surface and then diffuse into the interior, and the rate of junction migration has been measured, and analyzed, on the assumption that the formation rate of the acceptor (in flux) is proportional to the difference of the surface concentration from the equilibrium concentration.
Abstract: Undoped n-GaAs crystals grown from the melt have been heat-treated in a quartz ampoule under 3.4 Torr of arsenic vapor pressure at 650 to 800°C. The crystals were converted to p-type crystals by this heat treatment. Acceptor concentration in the crystals, which were in equilibrium with the ambient factors at temperature T, is expressed as 10-2.8exp (-0.6 eV/kT) per lattice site. The acceptors are initially formed at the crystal surface and then diffuse into the interior. Rate of junction migration has been measured, and analyzed, on an assumption that the formation rate of the acceptors (in flux) is proportional to the difference of the surface concentration from the equilibrium concentration. Results are: the formation rate constant kf(cm/sec)=10-0.6exp (-1.1 eV/kT) and the diffusion coefficient D(cm2/sec)=104.8exp (-2.5 eV/kT). These results cannot be explained in terms of copper contamination alone and are suggestive of an influence of Ga vacancies.
TL;DR: In this article, the rotations of tensile axis were used to detect slip systems in the [100] type and [110] type at high temperature (473°K) and at low temperature (153°K).
Abstract: Iron single crystals with various tensile axes near the [100]–[110] line were extended in the temperature range 153°K to 473°K. The crystals which had their tensile axis within about 10 degrees from the [100] axis showed large work-hardening at low temperatures and the crystals with other orientations showed small work-hardening. It was confirmed from the rotations of tensile axis that four slip systems operated in the [100] type crystals and two systems in the [110] type crystals at low temperatures. At high temperature (473°K), the [100] type crystals showed long and linear work-hardening in the latter stage of deformation and large elongations more than 100%, but the crystals near the [110] axis showed small work-hardening in the latter stage and also small elongations.
TL;DR: In this article, Si-and Ge-doped GaAs layers were obtained by a solution regrowth technique and their electric parameters ρ, µH, and p were found depending on the Si or Ge quantities in the melts.
Abstract: Si- and Ge-doped GaAs layers were obtained by a solution regrowth technique. They were p-type and their electric parameters ρ, µH, and p were found depending on the Si or Ge quantities in the melts. Ge-doped crystals had much larger µH values than Si-doped crystals. Si-doped p-n junctions showed I-V characteristics including tunneling and thermal components, while those of Ge-doped junctions had only a thermal component. Si-doped diodes showed photo responses originating from deep acceptor levels, while the photoresponses of Ge-doped ones were derived from a very shallow acceptor level. The same effects were seen in the emission spectra of these diodes. In the Si-doped ones, broad emission peaks were found at the longer wavelengths on account of the deep levels, while the emission spectra of Ge-doped diodes were sharp and concerned with the shallow acceptor level. An emission quantum efficiency of up to 2% was achieved in the Si-doped diode.
TL;DR: In this article, the authors applied holographic interferometry to obtain the contour lines of deformation lines of a plate by pure bending, according to the theory of elasticity, and from the angle between their asymptotes Poisson's ratio of the plate material is determined.
Abstract: Holographic interferometry is applied to obtain the contour lines of deformation of a plate by pure bending. According to the theory of elasticity they are hyperbolas and from the angle between their asymptotes Poisson's ratio of the plate material is determined. By the real time method an accuracy of 1% is attained in the case of steel plates. The dependence of the value on the plate shape is also examined.
TL;DR: In this article, the behavior of transitions and the nature of high-pressure phase in polytetrafluoro ethylene are studied using methods of ultrasonic waves, thermal expansion, differential thermal analysis and X-ray diffraction.
Abstract: Behavior of transitions and the nature of high-pressure phase in polytetrafluoro ethylene are studied using methods of ultrasonic waves, thermal expansion, differential thermal analysis and X-ray diffraction. A phase diagram is obtained in pressure range from 1 atm. to 6,500 kg/cm2 and in temperature range from room temperature to 165?C. Three phases are found; phase I above 30?C, phase II below 20?C, both at 1 atm. and phase III above 5,000 kg/cm2. The triple point is located at 75?C and 5,000 kg/cm2. Pressure dependence of transition temperatures is obtained as 15 and 9 degrees per 1,000 kg/cm2 for the 20?C and 30?C transitions at low pressure, 9 degrees per 1,000 kg/cm2 for both transitions at intermediate pressure range from about 3,000 to 5,000 kg/cm2, -13 and 50 degrees per 1,000 kg/cm2 for the II?III and the III?I transitions, respectively. It is suggested that the high-pressure phase (phase III) may be a closely packed but disordered phase.
TL;DR: In this paper, the authors measured electron mobility and carrier concentration in GaP crystals in the temperature range from 77°K to 400°K and found that the dominant process limiting the electron mobility is the intervalley scattering at 200-400°K, and the scattering by space charge regions at 77-200°K.
Abstract: n-GaP crystals were grown by slow cooling of Ga solution doped with various concentrations of Te. Electron mobility and carrier concentration in the crystals were measured in the temperature range from 77°K to 400°K. The analysis of mobility showed that the dominant process limiting the electron mobility is the intervalley scattering at 200–400°K and the scattering by space charge regions at 77–200°K. As for the intervalley scattering, the LA phonon near the X point, Tc=300°K, appeared to make a dominant contribution. The coupling constant for this phonon was estimated to be 0.7×109 eV/cm, just the same as the effective coupling constant for the dominant intervalley phonon in Si. The inhomogeneity in the crystals and the dependence of carrier concentration on doping level were also investigated and compared with those in the crystals grown by thermal gradient method and by vapor-phase epitaxy.
TL;DR: In this article, single domain fine particles about 150 A in diameter, of alloys of Fe, Co and Ni were prepared by evaporation in an atmosphere of argon at 3 Torr The particles were coupled with each other like a necklace.
Abstract: Single domain fine particles about 150 A in diameter, of alloys of Fe, Co and Ni were prepared by evaporation in an atmosphere of argon at 3 Torr The particles were coupled with each other like a necklace The X-ray diffraction analysis revealed that the lattice parameters of the alloy particles agreed with those of the original bulk alloys within an experimental error of 03% It was indicated, however, that they might be smaller than the latter within that error The maximum coercive force observed in Fe–Co alloys was about 15 kOe It was found that the oxidation of Fe–Co alloys can be prevented by adding some Ni The magnetic orientation of particles caused by application of a magnetic field during the evaporation was studied In a magnetic field of 05 kOe the necklace structure was aligned parallel to the field and a magnetic anisotropy of 35×105 erg/g appeared in this oriented sample This strong anisotropy is considered to be due to a shape anisotropy induced by alignment
TL;DR: In this article, the main peak position of infrared transmission spectra, the growth rate and the etch rate of the nitride films change respectively from 870 to 820 cm-1.
Abstract: Silicon nitride films are deposited on silicon wafer at low temperature by radio frequency glow discharge reaction of silane and nitrogen. The main peak position of infrared transmission spectra, the growth rate and the etch rate of the nitride films change respectively from 870 to 820 cm-1, from 0.8 to 6.5A/sec and from 150 to 5A/sec in 15% HF etchant with changing silane concentration from 0.1 to 2.5 mol %. The etch rate is larger than that of the thermally grown silicon nitride. The dielectric constant of nitride films changes from 8 to 5 with changing substrate temperature from 500 to 25°C. The nitride film deposited at as high temperature as 500°C shows a large hysteresis of C–V curve. The silicon nitride film deposited at the substrate temperature of 300°C and at the silane concentration of 0.5 mol % is stable against B–T treatment as well as thermally grown silicon nitride films. The value of flat-band surface charge ranges from 7 to 14×10''/cm2, the value is relatively small in comparison with that of thermally grown nitride.
TL;DR: In this paper, a method for obtaining the optical constants and thickness of thin metal films during deposition using an automatic recording ellipsometer is described, where the restored azimuth ψ, the differential phase change on reflection Δ and the transmittance T have been continuously meaured during the film deposition.
Abstract: A method for obtaining the optical constants and thickness of thin metal films during deposition using an automatic recording ellipsometer is described. The restored azimuth ψ, the differential phase change on reflection Δ and the transmittance T have been continuously meaured during the film deposition. The optical constants and the packing factor are calculated from these three quantities and are given as functions of film thickness for various deposition conditions.
TL;DR: In this paper, a plasma jet flame with helium gas was used for heating and a gram of particles were produced in five minutes continuously, and the produced particles of Fe-Co-Ni alloy were examined by electron microscope and X-ray diffractometer.
Abstract: Fine particles prepared by means of evaporation in inert gas have been expected to show various interesting physical or chemical properties, By the conventional method of heating by tungsten wire, only ten milligrams of particles were produced in one cycle of evaporation. In the present experiment a plasma jet flame with helium gas is used for heating and a gram of particles were produced in five minutes continuously. The produced particles of Fe-Co-Ni alloy are examined by electron-microscope and a X-ray diffractometer. The crystal structure, oxidation, lattice imperfection and sizes of the particles are discussed.