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A giant negative electrocaloric (EC) effect in a PbZrO3/(0.88BaTiO3-0.12 Bi(Mg1/2,Ti1/2)O3) (PZ/(BT-BMT)) multilayered composite ferroelectric (MCFE) thin film which is grown on Pt(111)/Ti/SiO2/Si(100) substrates by the sol-gel method is investigated in this work. The negative EC effect in the PZ/(BMT-BT) MCFE thin film is greatly higher than that in the PZ AFE thin film with an adiabatic temperature change (ATC) ΔT = 1.5 K. The ATC ΔT of the PZ/(BMT-BT) MCFE thin film is -32 K under the applied electric field change ΔE = 1151 kV/cm. The result is conducive to enhance the EC refrigeration efficiency greatly. [ABSTRACT FROM AUTHOR]

Electrical characterization of two GaAs p+-i-n+ mesa X-ray photodiodes over the temperature range 0°C to 120°C together with characterization of one of the diodes as an X-ray detector over the temperature range 0°C to 60°C is reported as part of the development of photon counting X-ray spectroscopic systems for harsh environments. The randomly selected diodes were fully etched and unpassivated. The diodes were 200μm in diameter and had 7μm thick i layers. The leakage current density was found to increase from (3±1)nA/cm-2 at 0°C to (24.36±0.05)μA/cm-2 at 120°C for D1 and from a current density smaller than the uncertainty (0.2±1.2)nA/cm-2 at 0°C to (9.39±0.02)μA/cm-2 at 120°C for D2 at the maximum investigated reverse bias (15V). The best energy resolution (FWHM at 5.9keV) was achieved at 5V reverse bias, at each temperature; 730eV at 0°C, 750eV at 20°C, 770eV at 40°C, and 840eV at 60°C. It was found that the parallel white noise was the main source of the photopeak broadening only when the detector operated at 60°C, at 5V, 10V, and 15V reverse bias and at long shaping times (>5μs), whereas the sum of the dielectricnoise and charge trapping noise was the dominant source of noise for all the other spectra. [ABSTRACT FROM AUTHOR]

By using ionic implantation and wafer bonding technologies, we peeled off a single-crystal LiNbO3 thin film in the atomic-layer smoothness from the surface of a bulk Z-cut LiNbO3 single crystal. X-ray diffraction patterns showed only (00l) orientation of the film. From positive-up-negative-down pulse characterization, we measured domain switching current transients under various short-pulse voltages, where we observed domain switching currents to occur separately at time after initial capacitor charging currents. This is similar to early observations in bulk ferroelectric single crystals, where apparent positive/negative coercive fields of domain switching determined from polarization-electric field hysteresis loops always equal maximum/minimum applied fields. However, after pulse stressing of the film for more than 1000 cycles, the domain switching speed is accelerated, where domain switching current overlaps with the initial capacitor charging current with a well-defined coercive field independent of the applied-field strength. Finally, we simulated the whole domain switching current transients with the assumption of the resistance degradation across interfacial passive layers between the film and electrodes. [ABSTRACT FROM AUTHOR]

Perovskite Aurivillius structure Bi5Ti3FeO15 (BTF) polycrystalline thin films were prepared by a chemical solution deposition route. The microstructure, electrical, and magnetic properties were investigated and in particular the optical properties of the BTF films were addressed. The coexistence of the ferroelectric and weak ferromagnetic properties at room temperature demonstrates the multiferroic behavior of the BTF films. The optical dielectric functions in the photon energy range of 1.13-4.13 eV have been extracted by fitting the experimental data in terms of the Tauc-Lorentz and Cauchy models. A direct interband transition is allowed and the energy bandgap is determined to be ∼3.3 eV for the BTF films. The weak absorption below the bandgap edge was observed and described by the Urbach band tail rule. Finally, the optical dispersion behaviors of the BTF films in the transparent region were explained using a single oscillator model. [ABSTRACT FROM AUTHOR]

The 2 mol % Mn doped Pb0.5Sr0.5TiO3 films were fabricated on sapphire substrates by chemical solution deposition. The complex dielectric functions and optical parameters of the films determined by transmittance spectroscopy in a broad temperature range of 80-500 K were investigated. Apparent thermally-driven band-gap energy shrinkage, line-width of interband electron transition broadening and the Urbach band tail behaviors were observed. The results can be mainly correlated with the renormalization of electronic band structure and band-gap energy due to the electron-phonon interaction, which is well established in terms of the Bose-Einstein model. [ABSTRACT FROM AUTHOR]

The InAs quantum dots (QDs) on an AlAs layer are grown on GaAs substrates by molecular beam epitaxy technique. The properties of materials and optics of such QD structures have been investigated by cross sectional transmission electron microscopy and photoluminescence (PL) techniques. It is discovered that the inhomogeneous strain filed mainly exists below InAs QDs layers in the case of no wetting layer. The full width at half maximums (FWHMs) and intensities of PL emission peaks of InAs QDs are found to be closely related to the thickness of the thin AlAs layers. The InAs QDs on an eight monolayer AlAs layer, with wide FWHMs and large integral intensity of PL emission peaks, are favorable for producing broadband QD superluminescent diodes, external-cavity QD laser with large tuning range. [ABSTRACT FROM AUTHOR]

The highly (l00) oriented Pb(Zr0.5Ti0.5)O3 thin films with different Fe3+ doping concentrations were fabricated on LaNiO3-coated silicon substrates by chemical solution deposition. And the microstructure, ferroelectric, leakage, and magnetic properties were investigated. The results indicate that incorporation of Fe3+ into PZT thin films can promote the degree of the lattice distortion and greatly improve the surface roughness. In comparison with the pure PZT sample, the ferroelectric hysteresis loops of Fe-doped PZT samples demonstrate larger and larger polarizations and coercive fields with the increase in Fe3+ doping amount. Moreover, leakage mechanism of present films evolves from the space charge limited conduction to the “modified” space charge limited conduction, and then returns to the space charge limited conduction with increasing Fe3+ doping concentration. The occurrence of exchange bias in these Fe-doped PZT samples implies that the magnetic exchange interaction can be explained by the bound magnetic polaron model. [ABSTRACT FROM AUTHOR]

The ac field (Eac) amplitude dependence of dielectric response has been investigated for poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) relaxor terpolymer films. The frequency dependence of the temperature of the permittivity maximum Tm can be well described by the Vogel–Fulcher relation for Eac in the range from 1.33 to 80 MV/m. Tm remains nearly constant at an Eac level lower than 13.3 MV/m, and starts decreasing with Eac increases further. The two parameters fitting to the Vogel–Fulcher relation, freezing temperature Tf and activation energy Ea, vary little for Eac below 26.7 MV/m and then Tf decreases, while Ea increases for higher Eac level. [ABSTRACT FROM AUTHOR]

In the present paper, the diffusion barrier properties of amorphous and nanocrystalline (NC) Ta films, and the interface microstructure of Ta/Cu were investigated as a function of annealing temperature. X-ray diffraction, scanning electron microscopy, cross-sectional transmission electron microscopy, and energy-dispersive spectrometer line scans were employed to study the microstructure evolution and diffusion behavior. It was found that an amorphous layer with a thickness of ∼5 nm formed at the interface of NC Ta/Cu at 450 °C annealing, while the interface of amorphous-Ta/Cu was still abrupt. Moreover, amorphous-Ta film acts as an effective diffusion barrier up to temperatures of 650 °C, which is higher than that for NC-Ta film. The fast diffusion along grain boundaries inside NC-Ta films is suggested to be responsible for the main failure of NC-Ta film. [ABSTRACT FROM AUTHOR]

The dc bias dependence of dielectric properties has been investigated for poly (vinylindene fluoride-trifluoroethylene-chlorofluoroethylene) relaxor terpolymer films. The frequency dependence of the temperature of the permittivity maximum, Tm, was analyzed using the Vogel–Fulcher (VF) relation. Two threshold fields, ∼30 and 160 MV/m were found in the electric-field dependence of Tm. Tm shows a minimum at ∼30 MV/m and a maximum at ∼160 MV/m. The VF parameters activation energy Ea and freezing temperature Tf respectively show a maximum and a minimum at ∼25 MV/m. [ABSTRACT FROM AUTHOR]

In this work we studied 65-nm-thick poly(vinylidene fluoride-trifluoroethylene) ferroelectric polymers films grown by Langmuir–Blodgett onto silicon substrates. Three dielectric anomalies have been unambiguously evidenced. The high temperature one near 380 K corresponds to the ferroelectric-paraelectric transition. The low temperature one near 270 K which is characterized by a β relaxation is attributed to structural defects in the crystalline phase leading to inhomogeneous strains detected by x-ray diffraction. At approximately 320 K, a Debye-like relaxation is clearly evidenced. Possible origins for this later relaxation are discussed. [ABSTRACT FROM AUTHOR]

A series of Mn doped Pb0.5Sr0.5TiO3 (PSMT) films with dopant concentrations from 0 to 10 mol % was fabricated on (111) Pt/Ti/SiO2/Si substrates by chemical solution deposition. Their microstructure, ferroelectric, and dielectric properties were investigated, and Mn doping was found to have a significant influence on the properties of (Pb,Sr)TiO3 film. The improved microstructure with increased grain size, remnant polarization, dielectric permittivity and its tunability by dc electric field, and reduced coercive field and dielectric loss was observed in the Mn doped samples. A PSMT film with 0.5 mol % Mn dopants exhibits the optimum characteristics with maximal remnant polarization (2Pr=25.28 μC/cm2), dielectric permittivity (1427) and tunability (74.5%, at 100 kHz), and minimal dielectric loss (0.015) at 1 kHz. The improvement was attributed to the improved microstructure, enhanced displacement of polar ions, and, most importantly, the suppression of oxygen-vacancy-induced ferroelectric domain pinning, which was well verified in terms of Rayleigh law. Finally, the evolution of oxygen-vacancy concentration modulated by the Mn doping in PSMT films was discussed. [ABSTRACT FROM AUTHOR]

In this work we studied 90 nm thick copolymer thin films of vinylidene fluoride (70%) with trifluoroethylene (30%) grown by Langmuir–Blodgett onto silicon substrates. The effects of two different bottom electrodes, namely, Al and LaNiO3 (LNO) are investigated. A Debye-like relaxation near 320 K is enlarged by LNO bottom electrode. X-ray diffraction pattern attests that two different crystallographic structures coexist below 340 K in film deposited on LNO. Compared with Al electrode, LNO electrode strongly increases defects or gauche segments in film and further weakens properties of film. [ABSTRACT FROM AUTHOR]

Using Landau–Devonshire (LD) phenomenological model, we investigate the dielectric and pyroelectric behaviors of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] ferroelectric Langmuir–Blodgett super thin films. Effects of homogeneous in-plane misfit strains and external electric field on the dielectric properties are combined to be investigated. The theoretical analysis indicates that phase transition temperature can be changed by in-plane misfit strains. Furthermore results show in-plane strains only change the position of peak but value of dielectric constant and pyroelectric coefficient. At one temperature (below phase transition temperature), compressive strain is more beneficial. Consequently the dielectric and pyroelectric responses can be optimized to satisfy various demands by the applied electric fields and tuning in-plane misfit strains. [ABSTRACT FROM AUTHOR]

The magnetic NiO/Fe19Ni81 nanostructure bilayer is deposited onto the colloidal spheres grown on a Si wafer by the self-assembly technology. The nanocap and the nanodot arrays form on the spherical surface and the Si substrate, respectively, which are confirmed by scanning electron microscopy and transmission electron microscopy measurements. Compared to the flat bilayer with the same composition deposited on the Si substrate, the exchange bias field HE from the nanocap is twice as large. The enhancement of HE in the nanocap is ascribed to the decreased thickness of the ferromagnetic layer induced by the sphere surface. The size and space of the biased caps are estimated based on the thickness variations induced by the sphere surfaces. [ABSTRACT FROM AUTHOR]

Nanoindentation creep tests were performed in the depth range from about 28 to 190 nm on nanocrystalline (NC) and ultrafine grain (UFG) Cu films. Pronounced indentation size effects on hardness, creep strain rate ([variant_greek_epsilon]), and strain rate sensitivity (mc) are observed. Both [variant_greek_epsilon] and mc are dependent not only on contact depth (hc) but also on grain size. The experiment results and analysis support that the creep deformation of NC and UFG Cu is dominated by grain-boundary-mediated process and diffusion along the interface of tip sample, respectively, under a critical hc and dislocation-mediated process begin to work as hc increases further. [ABSTRACT FROM AUTHOR]

The present paper relates to a method for synthesizing the photostimulable storage phosphor BaFBr:Eu2+ that features high stimulation characteristics for use in image plates. All previous synthesis routes consist of a multistep process whereas the presented route is a one-step synthesis. Starting compounds are BaCO3, NH4F, and NH4Br, as well as EuF3 where the ammonium compounds are highly volatile at temperatures below 300 °C. Their reaction products initiate the decomposition of BaCO3 and form BaFBr. The incorporation of F-centers and europium ions occurs at temperature exceeding 550 °C. The individual reaction steps are monitored by simultaneous thermal analysis (thermogravimetry/differential thermal analysis) and the gaseous reaction products are detected by in situ mass spectroscopy. Intermediate and final products are characterized by x-ray diffraction techniques to determine the involved phases. Photoluminescence spectra reveal the typical emission peak of Eu2+ accompanied by a redshifted emission band at 470 nm, which was assigned to oxygen incorporated into the BaFBr lattice. The synthesized powders exhibit small grain sizes well suited for the use in image plates. [ABSTRACT FROM AUTHOR]

The highly (00l)-oriented 5 mol % Mn doped Pb0.5Sr0.5TiO3 films with remarkable ferroelectric properties (2Pr=27.1 μC/cm2 and 2Ec=55.5 kV/cm) were fabricated on LaNiO3 coated silicon substrates by chemical solution deposition. The ac conductivity and the dielectric response of the films at various temperatures were studied. Hopping conduction accompanied by the dielectric relaxation at low frequencies was observed. The results can be correlated with the thermal-activated short range hopping of localized charge carriers through trap sites separated by potential barriers with different heights, i.e., localized electrons hopping between multivalence Mn sites (the activation energy of this hopping process is ∼0.4 eV), which is also established in terms of the correlated barrier hopping model. [ABSTRACT FROM AUTHOR]

The analytic models for size-dependent ordering and Curie temperatures of FePt nanoparticles have been proposed in terms of the size-dependent melting temperature. It is found that the order-disorder transition temperature TO and Curie temperature TC decrease with decreasing the particle size D, and the drop becomes dramatic once the size decreases to about 3 and 6 nm below for TO and TC, respectively. Moreover, the suppression in TC(D) is nearly twice as large as that in TO(D) when D is in the range of 5–20 nm. The accuracy of the developed model is verified by the recent experimental and computer simulation results. [ABSTRACT FROM AUTHOR]

Dielectric properties of the copolymer of vinylidene fluoride and trifluoroethylene films derived from the Langmuir–Blodgett technology have been investigated over the temperature range from 300 to 150 K at various frequencies. Below ∼240 K, peaks in the dielectric loss were observed to increase with increasing frequency. Nonlinear dielectric susceptibility and ferroelectric properties have been studied at different temperatures. The results show that the nonlinear dielectric susceptibility undergoes a remarkable change at ∼230 K. The results suggest a β relaxation, which is related to the freezing of the molecular motions in the amorphous phase in the polymer films. The anomaly in the electrical properties at ∼230 K is due to the freezing of the molecular chains motions. [ABSTRACT FROM AUTHOR]

The effect of nitrogen (N) doping on surface chemical composition and optical properties of Ba0.6Sr0.4TiO3 (BST) thin films have been investigated using x-ray photoemission spectroscopy (XPS) and transmittance measurement. It was found that the nitrogen doping induced Ti3+/4+ states and formed Ti–N bonds in BST films. With lower implantation energy, the oxygen vacancies can be effectively eliminated because of N dopants substitution. Unfortunately, the oxygen vacancies possibly increased when enhance implantation energy. In addition, the N-doped BST films indicated larger amount of perovskite phase and lower content additional phase at surface. The chemical shifts in XPS confirmed the forming of Ba–N and Sr–N bonds in N-doped BST films. The optical properties for as-grown and N-doped BST films were considered at wavelength range from 190 to 1100 nm. The optical constants, including refractive index n and extinction coefficient k, were calculated by fitting transmittance spectra with single Tauc-Lorenz and Lorenz models. The refractive index decreased largely with nitrogen implantation. Oppositely, the extinction coefficient increased with N dopants. The dispersion of refractive index in transparent region agreed well with a single electronic oscillator for all samples. The band gaps of N-doped BST films were much smaller than that of as-grown BST films because of localized N 2p states above the valence band edge. [ABSTRACT FROM AUTHOR]

Based on the theoretical model published by Chen et al. [Chem. Phys. Lett. 397, 222 (2004)], we present an efficient scheme for studying the mechanism of the electro-optic (EO) effect in perovskite-type ferroelectrics employing the electronic density-functional theory and the generalized gradient approximation. The results show that the main contribution to the EO effect in KNbO3 and LiNbO3 crystals comes from the relative displacements of the central metal ion and oxygen in the NbO6 oxygen octahedron induced by a low frequency applied electric field. These displacements change the band wave functions of the electrons in the crystals through electron-phonon coupling, which then affects the electronic response of the lattice to the incident optical wave (i.e., induces a change of refractive index). Furthermore, the relationship between the microstructure of perovskite-type ferroelectrics and the clamped EO effect and the physical meaning of the parameter βk(ij) published by Chen et al. are explained. [ABSTRACT FROM AUTHOR]

Based on the theoretical model published by Chen et al. [Chem. Phys. Lett. 397, 222 (2004)], we present an efficient scheme for studying the mechanism of the electro-optic (EO) effect in perovskite-type ferroelectrics employing the electronic density-functional theory and the generalized gradient approximation. The results show that the main contribution to the EO effect in KNbO3 and LiNbO3 crystals comes from the relative displacements of the central metal ion and oxygen in the NbO6 oxygen octahedron induced by a low frequency applied electric field. These displacements change the band wave functions of the electrons in the crystals through electron-phonon coupling, which then affects the electronic response of the lattice to the incident optical wave (i.e., induces a change of refractive index). Furthermore, the relationship between the microstructure of perovskite-type ferroelectrics and the clamped EO effect and the physical meaning of the parameter βk(ij) published by Chen et al. are explained. [ABSTRACT FROM AUTHOR]

92%Pb(Mg1/3Nb2/3)O3–8%PbTiO3 (PMNT) thin films have been prepared on Pt/Ti/SiO2/Si substrate with a LaNiO3 buffer layer and on sapphire substrate by a chemical solution deposition method. X-ray diffraction analysis shows that the PMNT thin films on Pt/Ti/SiO2/Si substrate are polycrystalline with (110)-preferential orientation. The optical properties of PMNT thin film in 2.5–12.5 μm and 200–1100 nm ranges have been investigated using infrared spectroscopic ellipsometry and ultravisible transmission spectra, respectively. The optical constants and thickness of the thin films have been obtained by fitting the measured ellipsometric parameter (Δ and Ψ) data and transmission spectrum with classical infrared and Tauc-Lorentz models. The optical band gap energy of the PMNT thin films on sapphire substrate is derived to be about 4.02 eV. [ABSTRACT FROM AUTHOR]

SrTiO3 thin films were deposited on vitreous silica substrates at various substrate temperatures (300–700 °C) by rf magnetron sputtering technique. The transition from amorphous phase to polycrystalline phase for the films occurred at the substrate temperatures of 300–400 °C. Their optical properties were investigated by transmittance measurements. The fitting method was used to calculate the refractive index and the film thickness from the transparent region of the transmittance spectra. The refractive index increased and the film thickness decreased with the substrate temperatures increasing. The dispersion of the refractive index was studied by considering a single electronic oscillator model. The band gaps of the films were estimated from Tauc’s law and showed a decreasing tendency to that of the bulk SrTiO3 with the substrate temperatures increasing. These results provide some useful references for the potential application of SrTiO3 films in integrated optics devices. [ABSTRACT FROM AUTHOR]

Electronic structure calculations of Na2SbF5, BaMgF4, and BaZnF4 are performed from first principles based on a plane-wave pseudopotential method. The linear optical properties and the static second-harmonic generation coefficients are also calculated. Furthermore, a real-space atom-cutting method is employed to analyze the respective contributions of the anionic groups and cations in Na2SbF5 to the optical response. The results show that the anionic groups (SbF5)2- in the crystal are quite favorable for producing larger microscopic second-order susceptibilities. [ABSTRACT FROM AUTHOR]

In this paper, using wet chemical solution deposition processes, the (100)-highly oriented LaNiO3 buffer layers were grown on both silicon and platinized silicon wafers and, sequentially, the highly (100)-oriented PbZr1-xTixO3 thin films with various compositions were obtained on them. The misfit elastic strains were found to be critical factors to determine the orientation of PZT thin films, even though the used LaNiO3 buffer layer reduces the lattice mismatch between PZT films and silicon wafers. For the PZT thin films with x=0.5 and 0.6 on the LaNiO3/platinized silicon substrate, the infrared optical constant, ferroelectric, and dielectric properties were characterized and analyzed with relation to the film orientation and the film grain size. It was found that the finite grain size effect here played a key role in determining these optical and electrical properties. With nanoferroelectric thin films, it is the most useful way of controlling both grain size and crystallographic orientation to tune performance of commercial film devices. [ABSTRACT FROM AUTHOR]

Self-assembled InAs quantum dots (QDs) have been fabricated by depositing 1.6, 1.8, 2.0 and 2.5 monolayer (ML) InAs on surfaces of the undoped-n[sup +] (UN[sup +]) type GaAs structure. Room temperature contactless electroreflectance (CER) was employed to study the built-in electric field and the surface Fermi level pinning of these QD-covered UN[sup +] GaAs samples. The CER results show that 1.6 ML InAs QDs on GaAs do not modify the Fermi level, whereas for samples with more than 1.6 ML InAs coverage, the surface Fermi level is moved to the valence band maximum of GaAs by about 70 meV (which is independent of the InAs deposition thickness) compared to bare GaAs. It is concluded that the modification of InAs coverage on the Fermi level on the GaAs surface is due to the QDs, rather than to the wetting layer. [ABSTRACT FROM AUTHOR]

We have fabricated a quantum dot (QD) structure for long-wavelength temperature-insensitive semiconductor laser by introducing a combined InAlAs and InGaAs overgrowth layer on InAs/ GaAs QDs. We found that QDs formed on GaAs (100) substrate by InAs deposition followed by the InAlAs and InGaAs combination layer demonstrate two effects: one is the photoluminescence peak redshift towards 1.35 µm at room temperature, the other is that the energy separation between the ground and first excited states can be up to 103 meV. These results are attributed to the fact that InAs/GaAs intermixing caused by In segregation at substrate temperature of 520 °C can be considerably suppressed by the thin InAlAs layer and the strain in the quantum dots can be reduced by the combined InAlAs and InGaAs layer. [ABSTRACT FROM AUTHOR]

Based on the quantum electrodynamics and using Einstein’s coefficient and Planck’s energy density, the stimulated emission cross section was given. The measured absorption of 0.5 at. % Nd-doped Nd:GdVO[sub 4] crystal was compared to the Judd–Ofelt (JO) theory. When applied, the JO theory of parity-forbidden electric–dipole transitions of rare-earth ions on noncentrosymmetric site lacking inversion symmetry demonstrates good agreement. An absorption band around 808 nm is suitable to match laser diode pumping. The branching ratio of the fluorescence emission and stimulated emission cross section at the emissive wavelength of 1064 nm are of great advantage to produce a laser output. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Examines spectral parameters of neodymium-doped yttrium orthovanadate (NYV) crystals. Absorption spectrum of neodymium ions doped in NYV; Width of the absorption band; Line intensity of the absorption spectrum of NYV.

A comparison of SQUID magnetometric and surface magneto-optic Kerr effect measurements of AF coupled Ni Co/Cu multilayers reveals the effect of total interface roughness on the magnetization process. The interface roughness increases with the bilayers period as indicated by low-angle x-ray reflectivity measurements. This leads to an external anisotropy which affects the surface and intersurface strains, causing an increase in magnetization.

Structure and magnetoresistance analyses of annealed sputtered (Ni81Fe19, Ni66Fe16Co18)/Ag granular multilayers reveal that the annealing temperature and the magnetic layer thickness, which control the mean magnetic particle size, influence the magnetoresistance (MR), thermal stability and the magnetoresistive sensitivities of the granules. Over 30% MR occurs at 4.2 K for an initial magnetic thickness of 4 angstroms. The magnetic thermal stability and consequently, the magnetoresistive sensitivities, are enhanced by increasing the thickness to 20 angstroms.

A method is described for preparing the photostimulable storage phosphor BaFBr:[Eu.sup.2+] featuring high stimulation characteristics for use in image plates. Photoluminescence spectra have shown the typical emission peak of [Eu.sup.2+] accompanied by a redshifted emission band at 470 nm and the powders have displayed small grain sizes well suited for the use in image plates.

Presents information pertaining to the Nd-doped barium sodium niobate crystals. Information on the temperature of the lattice constants; Confirmation of crystal structure; What the tetragonal tungsten bronze (TB) type crystals exhibits; Reference to the atomic absorption analysis; Details of results.