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We report a novel approach for large-scale gold nano-cone growth by utilizing the open nanopore channels of nanoporous gold films as both the template for nano-cone growth and the delivery channel of the reduction gas through the nano-pipes. Quasi-periodic nano-cone arrays uniformly sprout on the centimeter-sized free-standing nanoporous gold films. The sharp nano-cones give rise to ultrahigh surface enhanced Raman scattering for single molecule detection from the focused electromagnetic fields at the cone apexes. The large-scale nano-cone decorated nanoporous gold films may serve as high-performance SERS substrates for wide-ranging applications in ultrasensitive instrumentation and molecule diagnostics.

This paper reports the results of structural study on the ordered phases formed in Pd-rich Pd-Mn alloys adopting X-ray powder diffraction method. Formations of the tetragonal D023-type Pd3Mn, orthorhombic Pd2Mn and orthorhombic Pd5Mn3 reported by previous researchers have been confirmed. Rietveld refinement of the diffraction data of the latter two phases has determined precisely the atomic parameters and revealed the significance of the shifts of atoms in Pd2Mn. It is shown that the L10-type phase extends to about 33 at% Mn at high temperatures and Pd2Mn and Pd5Mn3 form via two-step ordering from the L10-type phase. A revised phase diagram on the Pd-rich side has been proposed. Discussion is given on the stability of the relevant ordered phases by making calculation of the total energy by the density functional method.

application/pdf, Measurements were made of in situ X-ray diffraction, electrical resistivity, and magnetic susceptibility for a series of newly found ternary alloys CuMPt6 with M = Ti, V, Cr, Mn, Fe, Co, and Ni. They possess, after appropriate heat treatment, the Cu3Au-type ordered structure, though the ordering is not complete for M = Ni. They are fairly good electrical conductor with a specific resistivity of around 6 × 10–3 ohm m. A general trend has been found in the magnetic property: nonmagnetic–spin-glass-like–ferromagnetic–paramagnetic, with increasing atomic number of M. The alloy with M = Mn, however, is specific among the seven alloys in that it undergoes secondary ordering into the cubic ABC6-type structure and is regarded as a counterpart of the Heusler alloy forming in the bcc systems.

Study of STM-excited light emission (STML) from organic films is significant for the potential applications to organic photoelectronics devices in nanometer scale. In this note, practical tips for measurements are given, focusing on how to detect very weak light signals efficiently. The mechanism of STML from molecules is described, and the technique of surface-plasmons enhanced molecular fluorescence is utilized for observation of intense light emission at far field regions. Provided are experimental results of STML from spin cast organic films of porphyrin series such as H2TBPP, H2TPP and PhTPP and conjugate polymer MEH-PPV under atmospheric conditions as well as in UHV as the examples.

セラミックスやエレクトロニクス産業の分野で広く使用されている封着加工用鉛ガラスの無鉛化は急務な課題である．本研究ではわれわれの研究グループが報告した封着加工用鉛フリーガラスである，41.8 mol% V2O5–3.1 mol% ZnO–17.6 mol% BaO–37.5 mol% TeO2（以下VTEと略記）ガラスと53.0 mol% V2O5–4.0 mol% ZnO–22.4 mol% BaO–20.6 mol% P2O5（以下VPと略記）ガラスの2つの組成系の実用化に向けた評価試験の検討を行った．評価試験内容としては，平面蛍光管の封着加工後のサーマルショック試験，耐圧試験，連続点灯試験を行った．対象実験として従来の鉛ガラス（以下Pbと略記）で作製した平面蛍光管と比較した結果，サーマルショック試験および加圧試験では鉛ガラスで作製された平面蛍光管と同等の熱衝撃および圧力衝撃性を有していることがわかった．また，連続点灯試験においても鉛ガラスを使用したものと同等の発光特性を有することがわかった．

We studied the scanning tunneling microscope-induced luminescence (STML) of conjugated polymer poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene (MEH-PPV) spun from the solutions with various concentrations on metal substrates Ag and Au. Characteristic molecular fluorescence with the intrinsic molecular vibronic peaks associated with the HOMO–LUMO transition appears in addition to the curve based on plasmon-mediated light emission from the metal substrate Ag or Au. We found that it is a necessary condition to observe molecular fluorescence that the plasmon-mediated light from the metal substrate, which depends on the substrate, is intense in the absorption band of the molecule.

We have investigated the structural evolution of one-dimensional (1D) gratings with high aspect ratios on Si(001) surfaces by high-temperature annealing. Gratings 2 µm in depth and having different pitches from 0.8 to 4.0 µm were annealed at 1100 °C under an ultrahigh vacuum condition. On the basis of observing the cross-sectional profiles of the gratings by scanning electron microscopy, the structural evolution and its dependence the grating period are characterized. The observed decay of the periodic surface structures, in which the wave heights are larger than 0.2–0.3 µm, is faster than the well-known exponential amplitude decay. We have also performed numerical simulation of the profile evolution of 1D gratings based on Mullins' theory, showing that surface self-diffusion is the predominant mass transport mechanism for the observed structural evolution.

Tunneling electrons-induced molecular fluorescence in organic film is enhanced by the surface plasmons. The plasmon enhancement can be expected not only by the plasmons of the substrate but also by the noble metal tip of scanning tunneling microscope (STM). In this report we investigate the tip effect in photoluminescence of meso -tetrakis(3,5-di-tertiarybutyl-phenyl)porphyrin (H 2 TBPP) film on indium tin oxide (ITO) combined with a STM. The experimental result shows the PL of molecules is enhanced by an Ag tip. This enhancement factor is evaluated larger than 2000.

We have studied the effect of the plasmon field on the STM-induced luminescence from porphyrin (H2TBPP) film on Au substrate. We have measured the spectrally resolved photon intensity map for the STM-induced luminescence, and found the similarity of their contrast for the photon maps for different spectral regions with different spectral origins, i.e. molecular fluorescence and the local plasmon induced luminescence from the substrate. This fact indicates that the molecular fluorescence is closely related with the plasmon field of the substrate, and supports that the STM-induced fluorescence from porphyrin film on Au is enhanced by the local plasmon field of the Au substrate.

The STM-induced luminescence of a conjugated polymer poly[2-methoxy-5-(2′-ethyl-hexyloxy)- p -phenylene vinylene] (MEHPPV) on metallic substrates of Ag(1 1 1), Ag, Au and Cu and ITO have been investigated in air at room temperature by using Ag or Pt–Ir tip. Molecular fluorescence of MEHPPV was observed from the polymer film on Ag(1 1 1), Ag and Au substrates, and all of them show an intensity enhancement compared to the pure substrates. A mutual enhancement between surface plasmon and molecular fluorescence is suggested for the STM-induced luminescence of MEHPPV on these substrates.

We report atomic scale flattening of surfaces of microstructures formed on Si wafers by furnace annealing. To avoid thermal deformation of the fabricated structures, advantage was taken of hydrogen annealing, which enables us to decrease the relaxation rate of Si surfaces due to surface hydrogenation. We examined cross-sectional shape and sidewall morphology of 3 μm deep trenches on Si(0 0 1) substrates after annealing at 1000 °C under various H2 pressures of 40–760 Torr. We successfully formed Si trenches with flat surfaces composed of terraces and steps while preserving the designed trench profile by increasing H2 pressure to 760 Torr.

A new class of ordered structures designated as of the ABC6-type has been found in the ternary CuMnPt6 alloy. It has a cubic symmetry with the unit cell consisting of 2 ⨯ 2 ⨯ 2 fcc unit cells, whose space group is Fm3m. A closely related structure with Cu replaced by Pt has also been found in the binary MnPt7 alloy. Both alloys undergo a double-step order – disorder phase transition, ABC6-type – Cu3Au-type – fcc disorder. A partial phase diagram was constructed on the Pt-rich side of Pt –Mn. MnPt7 is isostructural to CuPt7 previously found by Schneider and Esch, though the latter does not show the double-step transition. Within the Bragg–Williams approximation, the order – disorder phenomena in the three alloy systems can be successfully reproduced. It has been found that an ordering energy of negative sign, a preference of unlike pairs, between second-nearest neighbours plays a decisive role in the formation of the ABC6-type structure. An increase in the relative magnitude of the ordering energy suppresses the double-step transition and the ABC6-type phase forms directly from the disordered phase.

The dynamic behavior of steps involved in the relaxation of sharp corners in microfabricated structures on crystalline surfaces have been studied. We find that during the early stages of relaxation of slightly tapered trenches on Si(0 0 1), wide (1 1 0) terraces perpendicular to the substrate are formed near the corners of the trench sidewalls. The evolution of a step profile around the corner region, where step density abruptly changes, is analyzed using one-dimensional step models. It is found that, in case that mass transport occurs through surface diffusion, the preexisting steps on the trench sidewall are accumulated in the corner region, and extensive terraces are formed near the corners.

We have studied the decay kinetics of two-dimensional holes on SrTiO3(001) surfaces using scanning tunneling microscopy(STM). We have created nanoscale unit-cell-deep holes on (001) terraces using a STM nanofabrication technique, and have performed real-time observation of the decay of the holes in a temperature rage of 700 ∼ 800°C. From the observed time dependence of hole areas during decay, we have found that the rate limiting process of the decay is the surface diffusion. We have also investigated the effect of the existence of substrate steps and islands on the hole decay. [DOI: 10.1380/ejssnt.2006.307]

In order to obtain useful information on the transient process of phase transitions in ferroelectrics by various methods including calorimetry, the “mK-stabilized cell” of a small size has been developed. It is based on the heat flux differential scanning calorimeter (DSC) and has a temperature stability better than 1 mK. The “cell” can be used to change the temperature under nearly quasi-static conditions by an infinitesimally small rate not only on heating but also on cooling while passing through the transition points. It enables simultaneous measurements of endothermic heat and exothermic heat along with dielectric constants, displacement currents, etc. with a high degree of temperature resolution. X-ray diffraction measurements for sensing thermal anomalies are also possible by a minor modification of the “cell.” Precise and simultaneous measurements of thermal, electrical, and acoustic properties were carried out at the 403 K phase transition in BaTiO3 single crystal grown by the top-seeded solution growth method. It has been clarified that the exothermic heat at the transition on cooling has more useful information than the endothermic heat on heating; in the cooling process two thermal anomalies occur separately at T1 and T2 although the transition is in a narrow temperature range. It is recognized from other methods that the nature of the transition on cooling is not of a single but of multiple steps. Resonant ultrasonic measurements using the “cell” were carried out, after developing a new excitation method. The sample does not have a simple softening approaching the transition point on cooling but has different elastic moduli for the two thermal anomalies at T1 and T2. The dielectric constant also has an intermediate constant value between T1 and T2. The crystal structure in the room temperature phase below the transition point has been determined by X-ray diffraction. In this region, tetragonal and monoclinic structures coordinating with each other exist.

This paper describes a unified interpretation of unusual short-range order diffuse scattering intensity distribution, the appearance of intensity maxima simultaneously at the special points L and X of the reciprocal space, and of the formation of a variety of long-range ordered structures, including less common structures, in the face-centered cubic Cu–Pt alloys. Reassessment is first made of the ordered structures on the Pt-rich composition side and then it is shown that all the structures in the alloys are systematically described adopting the static concentration wave model, originally developed by Khachaturyan, with the two kinds of waves, L1 1 wave and L1 2 wave, and their combination. These waves are assumed to be still alive at temperatures above the order–disorder transition point with appreciably decreased amplitude and coherency length and lead to the appearance of the two types of diffuse intensity maxima. Comparison is made with the ordering behaviors in the well-known Cu–Au alloys, in which o...

The light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor with an electrolyte–insulator–semiconductor structure. The LAPS can have many measuring points integrated on the sensing surface, which are individually accessed by a light beam. By modifying the measuring points with different materials, a single sensor plate can be used as a multi-analyte sensor. In this paper, instrumentation and application of LAPS to multi-ion sensing and imaging are described. As a new application of LAPS, potentiometric imaging of a microfluidic channel is proposed.

A multisensor with a four-sectional membrane based on two Li- and two K-ionophores with different selectivities has been developed based on the laser-scanned silicon transducer (LSST), where the responses of the sensor sections have been measured by scanning the potentials at different points on the membrane surface. An artificial neural network (ANN) was employed for the analysis of mixed solutions. It has been demonstrated that by applying this hybrid sensor as a laser-scanned multisensor system, the concentration regions for the simultaneous determination of lithium and potassium ions in complex solutions have been enlarged significantly. It has been shown that using such a kind of multisensor system makes it possible to overcome the restriction of the selectivity in comparison with single sensors.

DNA thermal denaturation was observed by atomic force microscopy (AFM) on the surface of newly cleaved mica. It was found that at temperatures higher than the melting point, denaturation of DNA molecules took place and globular particles with size distribution were formed, and these particles could aggregate together to form fractal structures, which followed the diffusion limited aggregation (DLA) model. At 100 °C, degradation of DNA took place and small particles of about 20 nm in size were formed, and they also aggregated in fractal structures with a lower dimension. Evaporating speed of water affects the fractal dimension.

This paper gives a brief review of our recent work on a new method of nanoscale pattern formation of thin oxide film on Si substrate by using a scanning tunnelling microscope (STM): a field-emitted electron beam (e-beam) extracted from the STM tip is used for selective removal of the oxide film by e-beam-induced reduction and thermal annealing at moderately high temperatures (300–700 °C). The process is dependent on electron dose and the patterning is controllable by adjusting the emission current and exposure time. One can draw nanoscale open-window patterns directly on oxide-covered Si substrates, e.g. lines and concentric circles of a few tens of nanometres in line width and spacing. Such patterning on the Si oxide layer shows good reproducibility and flexibility of the nanofabrication method, which suggests a further development and application of this method in nanotechnology. The beam profile of the extracted e-beam is measured and the beam-energy dependence of the quantum yield of the process is derived. Based on the excitation function, we consider that the decomposition is activated by core-level excitations as is the Knotek–Feibelman mechanism. One can also make use of this technique to diagnose the Si/SiO2 interface topography on a sub-nanometre scale.

A K+-sensitive capacitive electrolyte-membrane-insulator-semiconductor (EMIS) sensor has been developed. The sensor utilizes a valinomycin-containing PVC-based membrane with different contents of plasticizer. This new type of sensor has been investigated in terms of its intrinsic characteristics, like impedance behavior, capacitance/voltage characteristics and frequency dependence. The optimized working conditions of the sensor and various membrane compositions have been studied with regard to the sensitivity performance in different electrolytes. The possibility of future applications for the measurement of extracellular potassium-ion concentrations are discussed.

X-ray diffraction study was performed for the atomic arrangements in Pt-rich (87.5 at.%) Cu–Pt alloy with the cubic structure both in the disordered and ordered states using single crystal samples....

Shape transformation of silicon trenches during annealing at high temperatures in a hydrogen ambient was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). By SEM observation of the trench profiles, we found that the rate of shape transformation increases with decreasing hydrogen pressure. Performing the simulation based on a continuum surface model, we show that the shape transformation during annealing in a hydrogen ambient is due to surface self-diffusion. By quantitative comparison of the results between the experiment and simulation, we estimated the diffusion coefficients. The obtained activation energy for surface diffusion under a hydrogen pressure of 40 Torr was much higher than that measured under ultrahigh-vacuum conditions. Furthermore, it was found by AFM observation of the trench sidewall surfaces that, during the thermal treatment, the large roughness of the as-etched trench sidewall surface decreased significantly due to surface self-diffusion of silicon atoms, resulting structures with atomically flat terraces and steps.

To examine the freezing and melting behavior of water in partially filled pores of porous silica, we performed X-ray diffraction measurements of water confined inside the cylindrical pores of SBA-15 with a pore radius of 3.9 nm as a function of temperature and pore filling. The freezing temperature increased continuously with increasing pore filling even in the region of capillary condensation. The results are related to the different states of the pore water depending on the degree of pore filling. On the other hand, the melting of the frozen pore water took place at a well-defined temperature of 256 K, independent of the level of pore filling. The X-ray diffraction patterns show that the freezing of the pore water results in formation of ice microcrystals with almost the same structure and size, irrespective of the different states of the pore water.

Phase transitions in BaTiO 3 single crystals were investigated by "mK-stabilized cell" having fine temperature stability. It enables us to make various kind of measurements not only on heating and but also on cooling at a very small rate of temperature change. Heat flow measurements have revealed that both the uppermost and the lowermost phase transitions are accompanied by complicated thermal anomaly, whereas the intermediate temperature transition shows a single peak. Taking into account, these results together with those of dielectric constant, displacement current and X-ray diffraction measurements, we suggest the paraelectric-ferroelectric transition in BaTiO 3 takes place in multi-step, leading to a complicated structure in the lower temperature region.

On the basis of the heat flow and X-ray diffraction measurements over a wide temperature range as well as precise heat flow and X-ray diffraction measurements employing "mK-stabilized cell" at the 320 K transition, we propose a predominant phase transition series in CsPbCl 3 . Existence of this new phase transition series has been examined on mixed crystals CsPbCl 3(1 m x ) Br 3 x ( x = 0.01, 0.05) and CsPbBr 3 single crystal by the heat flow and X-ray diffraction measurements, focusing on the hump of the heat flow which were observed from 320 K transition to 265 K in CsPbCl 3 .

The SiO2/Si interface morphology is observed with subnanometer resolution using an ultrahigh vacuum scanning tunneling microscope (STM). The oxide films are formed on flash-cleaned Si(001) surfaces by introducing O2 gas into an ultrahigh vacuum (UHV) chamber at 600°C, at room temperature, and at 600°C after oxidation at room temperature. The oxide overlayers are selectively removed by irradiation with a field-emission electron beam extracted from the STM tip at a substrate temperature of 300°C. We find that for the oxide overlayer formed under a saturation condition at room temperature, there are many islands and vacancies on the terraces and the terrace–step structure is hardly recognizable. When the sample is further oxidized at 600°C for 10 min at a pressure of 2.0 ×10-4 Pa, we find that the terrace–step structure becomes conspicuous, in good agreement with the previous observations by Watanabe et al. [Phys. Rev. Lett. 80 (1998) 345].

Using ultrahigh vacuum scanning tunneling microscopy, we have studied the early stages of the epitaxial growth of CaF2 films on Si(111) at 630°C at a slow deposition rate of 0.2 monolayer (ML) per minute. After formation of CaF interface layer, we observe the film grows in the sequence of step edge decoration, one-dimensional islands growth on the terrace, formation of clusters of the islands, coalescence of the island cluster and filling of gaps between the one-dimensional islands in the cluster and between the island clusters to complete a layer. By such a sequence, epitaxial CaF2 films with atomically flat surface could be grown in layer-by-layer fashion up to 3 ML. The growth mode is discussed in relation to kinetic phase diagram [M. A. Olmstead: Thin Films: Heteroepitaxial Systems, eds. W. K. Liu and M. B. Santos (World Scientific, Singapore, 1999) Chap. 5].

A software feedback control system for the constant-current-mode operation of the light-addressable potentiometric sensor (LAPS) was developed. The constant-current-mode LAPS (CLAPS) is suitable for online monitoring and recording of changes in the pH value or the ion concentration. An enzyme LAPS was fabricated by adsorptive immobilization of penicillinase on the pH-sensitive layer of Ta2O5. This sensor was operated in the constant-current-mode and the detection limit for penicillin G was found to be at least as low as 100 µM.

Atomic force microscopy (AFM) has been used for tribological studies of Si surfaces covered by oxide layers of various kinds: chemical oxides prepared by the SC1 (NH4OH/H2O2/H2O) and the SC2 (HCl/H2O2/H2O) treatments and a thermal oxide. In the case of the SC1 chemical oxide, the oxide layer was scratched and the underlying Si substrate was ploughed by the Si3N4 AFM tip. On the other hand, no wear of the sample was noted on the other surfaces: the AFM often produced elevated patterns in the shape of the scanned area, which were no longer visible after HF etching. By annealing the SC1-treated surface in N2 gas at above 200°C for 30 min , the oxide layer could not be scratched any more. By soaking the thermal oxide in KOH, the oxide layer was then scratched. It is concluded that the presence of OH bases is the necessary condition for the nano-scratching of the oxide layers.

Atomic force microscopy (AFM) has been used for nanotribological studies of silicon surfaces covered by oxide layers of various kinds: chemical oxides prepared by SC 1 (NH4OH/H2O2/H2O) and SC 2 (HCl/H2O2/H2O) treatments, a thermally treated silicon surface and a H-terminated oxide-free silicon surface. Only in the case of SC 1 chemical oxide, scratching of the oxide and ploughing of the silicon by a Si3N4 AFM tip were observed. On the other hand, no wear of the sample was noted on other surfaces. By annealing the SC 1-treated surface in N2 gas above 200oC for 30 min, the oxide layer could not be scratched. By soaking the thermal oxide in KOH, the oxide layer was then scratched. It is suggested that the presence of OH bases is a requirement for the nano-scratching of the oxide layers.

We report here a nanofabrication result on a 2.7 nm thermal oxide layer using the low-energy e-beam/scanning tunneling microscope (STM) technique in conjunction with thermal annealing, in which line windows with average width of 50 nm can be formed. Comparing to the low-energy e-beam processing on thin layers of native Si oxide, this nanofabrication shows a uniform etching of the electronic industry compatible Si oxide, with which nanoscale trenches can be formed. In addition to demonstrating further the nanofabrication capability of this technique on the thermal oxide, the results present critical evidence to our previous discussions on the mechanism of the low-energy e-beam/STM nanofabrication.

Precise measurements of the phase transition in ferroelectrics of perovskite structure were carried out with a temperature stability better than a few millikelvin using simple and versatile “mK-stabilized cells” developed for calorimetric and X-ray diffraction studies. Noticeable closely spaced thermal anomalies were observed within 0.1 K of the phase transitions from cubic to tetragonal phases in CsPbCl3 and BaTiO3. CsPbCl3 has two anomalies (heating) and three (cooling) at 320 K that are well separated. Corresponding X-ray diffraction changes in the interplanar spacing and its appearance of superlattice reflections were detected. It is suggested that the condensation of the M3 soft phonon mode of PbCl6 is inadequate to explain these “multistage transitions”.

The chemical imaging sensor is applied to electrophysiological measurement of a neural cell. In this method, neural cells are cultured directly on the sensing surface, and a laser beam is used to specify a cell to be measured. The amplitude of the ac photocurrent induced by the laser beam is measured to detect the change of the membrane potential of the cell. In this study, the membrane potential of the cell is varied by injection of a dc current, and it is demonstrated that the ac photocurrent signal responds to the membrane potential. This method would enable noninvasive electric measurement of neural cells, networks or tissues under long-term culture.

Structural phase transitions in the title mixed crystals with the concentration of x =0.95, 0.90 and 0.80 having the cubic NaCl-type structure at room temperature were studied by X-ray single crystal precession method in the temperature range between 300 K and 85 K. An x - T phase diagram has been determined, in which the relation among the cubic phase, ITP (a so-called intermediate temperature phase) and the orthorhombic phase (space group I m m m ) has been established. ITP consists of three crystal forms, monoclinic, triclinic I and triclinic II, forming a multidomain hybrid structure with a definite orientation relationship to the cubic lattice. The former two forms were the same as those found in the low temperature phase of RbCN as well as in the intermediate metastable phase of KCN, while the latter form is the one found in the mixed crystals. The orthorhombic phase is the same forming in KCN and NaCN at low temperatures. It has been found that, although sample crystal breaks up into the multidomai...

Combined with thermal annealing, the locally confined low energy electron-beam from a scanning tunneling microscope (STM) tip can be used for nanofabrication of Si oxide film on Si substrate as nano-lithography mask; the oxide layer within the field emission a-beam exposed area can be decomposed, and then evacuated from the surface at elevated temperatures of about 600°C. Different manometer scale patterns of the oxide windows on Si substrate such as dot window arrays, lines, and circles can be formed. The minimum feature size attained so far is 25nm and the rms edge roughness of line patterns is less than 3.5nm. Mechanism and controllability of the STM nanofabrication processing are discussed.

Using pulsed-neutron diffraction technique, we performed in situ measurements of structural ordering in Pt-rich Pt–Mn binary alloys and CuMnPt 6 ternary alloy. The observed diffraction patterns at various temperatures have revealed two ordered phases in these alloys. Below the order–disorder transition temperature, a Cu 3 Au type ordered structure is formed as an ordering within the fundamental face-centered cubic lattice to subdivide the lattice into two sublattices formed by face-centered sites (first sublattice) and corner sites (second sublattice). At low temperature, an ABC 6 type ordered structure is formed as an ordering within the second sublattice to subdivide the lattice further into two sublattices formed by alternating (1 1 1) planes. A secondary ordering in the alloys is discussed in terms of two order parameters in the ABC 6 type structure utilizing the method of static concentration waves originally proposed by Khachaturyan. It is shown that the degree of order for the secondary ordering is rather low for the CuMnPt 6 ternary alloy.

A simple and versatile method of high-temperature stability is presented for x-ray diffraction measurements near room temperature. The small sample cell for the measurements possesses coaxial multishells to guarantee the temperature homogeneity in the shells. It is capable of being directly and easily mounted on the commercially available goniometer head. A double-stage temperature control is adopted using both a heater and a thermoelectric module. The temperature is regulated by an optimized proportional integral derivative (PID) control. The base-line stability of the temperature at the sample stage in the cell is within ±0.5 mK. X-ray precession patterns of PbCsCl3 single crystal were taken at two temperatures separated by 30 mK across the phase transition point, showing the appearance and disappearance of a diffraction spot from the superstructure.

The intensity of light scattered by a submicron particle on a film-coated semiconductor substrate is calculated as a function of the thickness of the film using the coupled-dipole method. The result of calculation reproduces the experimentally observed features, i.e., the oscillatory dependence of the scattering intensity on the thickness and the enhancement of the scattering intensity for very thin films. The enhancement is reproduced only when the dipole-dipole interaction between the particle and the substrate is included in the calculation. Using the method we propose, the scattering intensity can be calculated for an arbitrary size and shape of particle on an arbitrary thickness of film.

Crystal structure of RbCN has been investigated on single crystals by X-ray precession photographic method at temperatures ranging from 300 to 85 K. At about 125 K, the crystal transforms from the cubic NaCl-type phase into a low-temperature phase in which a monoclinic and a triclinic forms coexist. Both the forms are related with the specific crystallographic orientation to the cubic lattice. The lattice constants of the monoclinic form are a M =4.81(1), b M =4.87(1), c M =7.92(1) A, β=122.7(1)° at 85 K, and the structure is A-base-centered with the space group A2/m. The lattice constants of the triclinic form are a T =9.79(1), b T =4.62(1), c T =4.88(1) A, α=121.1(1)°, β=119.4(1)°, γ=90.0(1)° at 85 K. Crystallographic relationships between these forms and the cubic form are presented. The results are compared with the findings in the related compound KCN.

In this article LaF3 films in LaF3/Si structure have been investigated for the measurement of fluoride ions in aqueous solution with higher accuracy using light-addressable potentiometric sensing technique. LaF3 films were directly grown on Si by vacuum evaporation. The effects of LaF3-thickness and annealing on the fluoride-sensitivity of the LaF3/Si structures have been studied. Accordingly four different LaF3/Si structures with various thickness of LaF3 (5/50/150nm) layer were fabricated. The structures are annealed at 400ºC for 10 minutes. The un-annealed LaF3/Si structures show very poor fluoride sensitivity. As predicted in the theoretical study structures with thinner LaF3 offer better steepness of the photocurrent characteristics that indicates better accuracy in fluoride concentration measurement. Among the annealed structures, the one prepared with 150nm LaF3 layer shows the best fluoride sensitivity of ≈ 54.5mV/pF in the range of pF1-pF4. Experimental results show a good promise for LaF3/Si structure as a light-addressable potentiometric sensor that can be used for the sensing and imaging the distribution of fluoride ion in aqueous medium with higher accuracy.Keywords: Light-addressable potentiometric sensor (LAPS), Fluoride sensor, Capacitive EIS structure

Near- and far-field characteristics of a germanium soft x-ray laser at the wavelengths of 23.2–23.6 nm ( J = 2-1 transitions) and 19.6 nm ( J = 0-1 transition) are given for quantitative evaluation of the germanium laser for holographic applications. In-line Gabor holography of simple structured objects, such as thin opaque fibers and a standard electron microscope test specimen, is demonstrated. The holograms were recorded on PMMA (polymethyl methacrylate) photoresists and Ilford Q-plates. The holograms recorded on PMMA were retrieved with an atomic force microscope. The object image was reconstructed by numerical reconstruction with phase retrieval algorithm, resulting in a clear, ghost-free image with sharp edges which infer sub- μ m resolution. Future directions for x-ray laser holography are briefly discussed.

High quality diffraction data of high pressure phases of bismuth, Bi III, Bi III' and Bi IV, were obtained by using the high energy Synchrotron Radiation. Based on the observed diffraction data, crystal structures of these phases have been solved as, Bi III : tetragonal structure with unit cell parameters of a=0. 8680 ± 0. 0005 nm and c=0. 4248 ± 0. 0003 nm at 3. 2 GPa, Bi III': the same structure as Bi III, and Bi IV : monoclinic structure with unit cell parameters of a=0. 6463 ± 0. 0005nm, b=0. 6460 ± 0. 0005nm, c=0. 6582 ± 0. 0006 nm and γ=118. 84 ± 0. 05°at 3. 9 GPa and 503 K. The relations of atomic arrangements between Bi III and Bi V, Bu IV and Bi V are discussed.