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1.
Potassium ion conducting solid electrolytes based on potassium monoferrite have been prepared by substituting pentavalent
phosphorus cations for Fe3+. The highest conductivity of K2 − 2x
Fe2 − x
P
x
O4 is achieved in the range x = 0.05−0.10: 7.1 × 10−3 S/cm at 300°C and 1.6 × 10−1 S/cm at 700°C. The rise in the conductivity of KFeO2 upon phosphorus doping is due to the formation of potassium vacancies.
Original Russian Text ? E.I. Burmakin, G.Sh. Shekhtman, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 8,
pp. 995–998. 相似文献
2.
S. Kh. Estemirova A. M. Yankin S. G. Titova V. F. Balakirev Yu. E. Turkhan 《Inorganic Materials》2008,44(11):1251-1256
A structural phase diagram of La1 − x
Ca
x
MnO3 + δ (0 ≤ x ≤ 0.2) solid solution in air has been constructed for the first time, and the equilibrium T-x fields of the monoclinic, orthorhombic, and rhombohedral phases in this system have been outlined. The transitions between
these phases are accompanied by sharp changes in lattice parameters, suggesting that they are first-order.
Original Russian Text ? S.Kh. Estemirova, A.M. Yankin, S.G. Titova, V.F. Balakirev, Yu.E. Turkhan, 2008, published in Neorganicheskie
Materialy, 2008, Vol. 44, No. 11, pp. 1387–1392. 相似文献
3.
Ceramics in the solid solution of (1 − x)Pb(Zn1/2W1/2)O3–xPb(Zr0.5Ti0.5)O3 system, with x = 0.80, 0.85, 0.90, and 0.95, were synthesized with the solid-state reaction technique. The perovskite phase formation in
the sintered ceramics was analyzed with X-ray diffraction. It shows that the rhombohedral and the tetragonal phases coexist
in the ceramic with x = 0.90, indicating the morphotropic phase boundary (MPB) within this pseudo-binary system. Dielectric and ferroelectric properties
measurements indicate that the transition temperature decreases while the remanent polarization increases with the addition
of Pb(Zn1/2W1/2)O3. In the composition of x = 0.85 which is close to the MPB in the rhombohedral side, a high piezoelectric property with d
33 = 222 pC/N was observed. 相似文献
4.
The physicochemical properties of (1 − x)CsH2PO4/xSiP
y
O
z
(x = 0.2–0.7) composites containing fine-particle silicon phosphates as heterogeneous additives have been studied at different
humidities. The introduction of silicon phosphates suppresses the superionic phase transition of CsH2PO4 and increases the low-temperature conductivity of the materials, which depends significantly on humidity. The CsH2PO4-SiP
y
O
z
materials offer high conductivity (∼3 × 10−3 to 10−2 S/cm at ∼110–230°C) at low water vapor pressures (3 mol % H2O). Amorphization of the CsH2PO4 in the composites markedly changes its thermodynamic properties. The effect of long-term isothermal holding (210°C, 3 mol
% H2O) on the conductivity of the composites has been studied.
Original Russian Text ? V.G. Ponomareva, E.S. Shutova, G.V. Lavrova, 2008, published in Neorganicheskie Materialy, 2008, Vol.
44, No. 9, pp. 1131–1136. 相似文献
5.
C. H. Ho S. T. Wang Y. S. Huang K. K. Tiong 《Journal of Materials Science: Materials in Electronics》2009,20(Z1):207-210
Structural and luminescence properties of GaSe1−x
S
x
(0 ≤ x ≤ 1) series optical materials have been studied by X-ray diffraction, photoluminescence (PL), and piezoreflectance (PzR)
measurements. Powder X-ray diffraction patterns showed the whole series layers present three different kinds of stacking formula
with respect to the compositional change of sulfur from x = 0 to x = 1. The comparison of PL and PzR spectra reveals that the GaSe1−x
S
x
layers have three different kinds of stacking phase from x = 0 to x = 1. The PL results show the whole series GaSe1−x
S
x
layers emit the luminescences from red to blue visible region. The PL and PzR spectra of the GaSe1−x
S
x
are analyzed. The structural variation in between the layers is discussed. 相似文献
6.
I. V. Belen’kaya O. A. Savinskaya M. A. Neklyudova A. P. Nemudry 《Inorganic Materials》2011,47(12):1347-1355
We have synthesized Sr1 − x
Pb
x
FeO3 − δ (x = 0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.5) perovskite-like materials and studied their structure by X-ray diffraction, M?ssbauer
spectroscopy, and electron microscopy. According to the X-ray diffraction data, the Pb solubility limit in the perovskite
structure is x ≈ 0.15. The materials with x = 0.05 and 0.1 contained Pb1.33Sr0.67Fe2O5 inclusions 10–30 nm in size. Using chronopotentiometry and temperature-programmed desorption, we have estimated oxygen mobility
in the materials with x = 0.05 and 0.1. The results demonstrate that Pb doping increases oxygen mobility in the strontium-ferrite-based materials. 相似文献
7.
Tadashi Ishigaki Kenji Toda Tomoaki Watanabe Naonori Sakamoto Nobuhiro Matsushita Masahiro Yoshimura 《Journal of Materials Science》2008,43(14):4749-4752
In order to synthesize compounds of various Perovskite-related structures, we have utilized a novel “melt synthesis technique”
for phosphors rather than the conventional solid state reaction techniques. The solid state reactions require multi-step processes
of heating/cooling with intermediate grindings to make homogeneous samples. However, for the melt synthesis, it is possible
to make a homogeneous sample in a single step within a short period of time (1–60 s) due to the liquid phase reaction in the
molten samples, which were melted by strong light radiation in an imaging furnace. In this study, we have prepared a red-phosphor
CaLaGaO4:Eu3+ which has a perovskite—related layered K2NiF4 structure. Well-crystallized CaLa1−x
Eu
x
GaO4 samples with the K2NiF4 structure have been obtained up to x = 0.25, but there was the formation of an olivine phase when x = 0.5–1.0. The red emission at 618 nm increased with the increasing value of x up to x = 0.25.
相似文献
Tadashi IshigakiEmail: |
Masahiro Yoshimura (Corresponding author)Email: |
8.
I. G. Atabaev N. A. Matchanov E. N. Bakhranov M. U. Khazhiev 《Inorganic Materials》2008,44(7):675-679
We have studied the properties of Si1 − x
Ge
x
-based p-i-n structures and Schottky barriers in which the i-region had been produced via compensation with gold. The results demonstrate that the use of a guard ring in p-Si1 − x
Ge
x
〈Au〉 structures reduces the room-temperature reverse leakage current by two to three orders of magnitude. Such structures
have sufficiently small reverse currents and a barrier on the order of 0.75 eV. p-Si1 − x
Ge
x
〈Au〉-based guard-ring structures are suitable for the fabrication of IR and nuclear detectors.
Original Russian Text ? I.G. Atabaev, N.A. Matchanov, E.N. Bakhranov, M.U. Khazhiev, 2008, published in Neorganicheskie Materialy,
2008, Vol. 44, No. 7, pp. 775–780. 相似文献
9.
M. Y. Lin Y. F. Wang D. C. Ling H. S. Sheu H.-C. I. Kao 《Journal of Superconductivity and Novel Magnetism》2010,23(5):721-724
A series of single phase (La1−x
Sr1+x
) (Mn0.5Co0.5)O4 (0≤x≤0.40) materials with a tetragonal K2NiF4 structure was prepared by a solid state reaction method at 1400 or 1450 °C with a short period of heating time. Powder X-ray
diffraction (XRD) and the Rietveld refinement method were employed for the structural analysis. Unit cell a- and c-axes decrease with increasing amount of Sr substitution. A discrepancy between the zero-field-cooled and the field-cooled
magnetization is observed in all samples investigated below a characteristic temperature, T
*, which likely arises from the canted nature of spins or the random freezing of spins. It appears that T
* decreases with increasing amount of Sr substitution, which is possibly due to the enhancement of chemical pressure induced
by Sr and a corresponding increases of the valence of Mn and/or Co. 相似文献
10.
Kandasami Asokan Jae Young Park Sunwoo Choi Changhwan Chang Sang Sub Kim 《Nano Research》2010,3(4):256-263
We experimentally investigate the stabilization of the anatase phase of Ti1−x
Sn
x
O2 (x < 0.5) nanofibers when synthesized by an electrospinning method. The as-spun nanofibers became nano-grained, polycrystalline
nanofibers after calcination and the diameters of the nanofibers depend on Sn content. Stabilization of the anatase phase
in Ti-rich compositions and incorporation of Sn ions were confirmed by X-ray diffraction, Raman, X-ray absorption near-edge
structure, and photoluminescence (PL) spectroscopies. Results from the PL study also demonstrated the tunable nature of the
optical properties, with the emission maximum shifting towards higher wavelength with increasing Sn concentration.
相似文献
11.
The elastic (Young’s modulus) and inelastic (internal friction) properties of amorphous (Co45Fe45Zr10)
x
(Al2O3)100 − x
nanocomposites with various relative contents of the metallic and dielectric phases have been studied. In the region of low
temperatures, the composites exhibit a peak of the internal friction (at ∼240 K), the intensity of which increases with the
content of the metallic phase. For compositions above the percolation threshold, the temperature dependence of the internal
friction exhibits exponential growth above 300°C, which is related to the migration of vacancy-like defects in the amorphous
structure of the metallic phase. 相似文献
12.
Chun Li Qian-feng Fang Xian-ping Wang Guo-guang Zhang 《Frontiers of Materials Science in China》2008,2(1):42-47
Based on the novel oxygen ion conductor La2Mo2O9, a series of Fe-doped samples of La2Mo2−x
Fe
x
O9−δ
(x = 0, 0.025, 0.05, 0.1) was prepared by conventional solid-state reaction method. The structure, phase transition, oxygen
ion diffusion and electrical conductivity were studied with X-ray diffraction (XRD), differential scanning calorimeter (DSC),
direct current (dc) resistivity, and dielectric relaxation (DR) measurements. One DR peak associated with the short-distance
diffusion of oxygen vacancies was observed in both temperature and frequency spectra. The activation energy for oxygen ion
diffusion in Fe-doped La2Mo2O9 samples was smaller than that in un-doped samples. Fe doping can increase the ionic conductivity of La2Mo2−x
Fe
x
O9−δ
samples as well as the ionic transference number in the temperature range from 680°C to 400°C in comparison with the un-doped
samples, although the electronic conductivity slightly increases. It is found that because of the small solubility of Fe2O3 in La2Mo2O9 (<5%), Fe doping cannot suppress the phase transition that occurred around 570°C, but 2.5% K doping at La site at the same
time (e.g. in sample La1.95K0.05Mo1.95Fe0.05O9−δ
) can completely suppress this phase transition and increase conductivity at lower temperatures. 相似文献
13.
H. Khelifi A. Aydi N. Abdelmoula A. Simon A. Maalej H. Khemakhem M. Maglione 《Journal of Materials Science》2012,47(4):1943-1949
Lead-free (1 − x)NaNbO3/xBa(Ti0.5Sn0.5)O3 (x = 0.1, 0.125, 0.15, 0.175, 0.2, and 0.3) ceramics were elaborated by the conventional ceramic technique. Sintering has been
made at 1523 K for 2 h. The crystal structure was investigated by X-ray diffraction with CuKα radiation at room temperature.
As a function of composition, these compounds crystallize with tetragonal or cubic symmetry. Dielectric measurements show
that the materials have a classical ferroelectric behavior for compositions in the range 0.10 ≤ x ≤ 0.15 and relaxor one for compositions in the range 0.15 < x ≤ 0.30. Temperatures T
C or T
m decrease as x content increases. The ferroelectric behavior has been confirmed by hysteresis characterization. For x = 0.1, a piezoelectric coefficient d
31 of 42.146 pC N−1 was obtained at room temperature. The evolution of the Raman spectra was studied as a function of temperature for x = 0.1. 相似文献
14.
Mustafa Yilmazlar Huseyin Aydin Ahmet Varilci Cabir Terzioglu 《Journal of Materials Science》2007,42(21):9030-9036
The effect of the partial substitution of Ca by Sm in the Bi-2223 superconducting samples have been investigated in terms
of X-ray diffraction (XRD), EDXRF (Energy Dispersive X-ray Fluorescent), magnetoresistivity, critical temperature, transport
critical current density, and ac susceptibility measurements. The samples were prepared by the conventional solid-state reaction
method. XRD patterns are used to calculate lattice parameters and phase ratio of the Bi-2223 samples. The volume fraction
was determined from the intensities of Bi-2223 and Bi-2212 peaks. The room temperature XRD patterns of the samples showed
the presence of Bi-2223 phase decreases with increasing the Sm content. We estimated the transition temperature of the samples
from the resistivity versus temperature measurements in dc magnetic fields up to 0.6 T. We observed that transition temperature,
T
c
, and transport critical current density,
, depend on the Sm substitution. They both decrease with increasing the Sm substitution. We extracted the peak temperature,
T
p
, and the pinning force density from our previous ac susceptibility measurements. The pinning force density decreased with
increasing the Sm content. The possible reasons for the observed decreases in critical temperature and critical current density
due to Sm substitution were discussed. 相似文献
15.
We have studied the effect of heat treatment in mercury and sulfur vapors on the magnetic susceptibility of Hg1 − x
Mn
x
Te1 − y
S
y
crystals. Measurements were performed by the Faraday method in the temperature range 77–300 K at H= 318 kA/m before and after heat treatments. The results demonstrate that the behavior of the magnetic susceptibility can
be understood in terms of Mn-S-Mn-S, Mn-Te-Mn-Te, and (mixed) Mn-Te-Mn-S clusters of different sizes with indirect antiferromagnetic
exchange interaction between the Mn atoms through the chalcogen atoms. Heat treatment in sulfur and mercury vapors leads to
the formation of new clusters or changes (increases or decreases) the size of already existing clusters.
Original Russian Text ? P.D. Maryanchuk, E.V. Maistruk, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 5,
pp. 549–554. 相似文献
16.
F. S. Wang Y. L. Chen C. H. Cheng Y. Zhang Y. Zhao 《Journal of Superconductivity and Novel Magnetism》2010,23(6):1035-1038
La1−x/2Pr1−x/2Ce
x
CuO
y
(LPCCO) samples with doping level up to 20% have been synthesized and their electronic and superconductive properties are
studied. X-ray diffraction revealed that the LPCCO system is a pure phase system with a T’214 structure. Magnetic and resistive
measurements show that the system is superconducting at 0.08≤x<0.20 with T
cmax=25 K at x=0.12. An anti-ferromagnetism transition was also observed in under-doped PLCCO (x=0.05) with the window width of the anti-ferromagnetism phase being significantly narrower than that NCCO and PCCO systems.
The behavior of the Ce doping is compared with Sr doping in this system, and the mechanism is discussed. 相似文献
17.
Rachna Selvamani Gurvinderjit Singh A. K. Sinha V. S. Tiwari 《Journal of Materials Science》2012,47(4):2011-2015
X-ray absorption spectroscopy (XAS) and impedance spectroscopy have been used to study the oxidation state of chromium in
(Na0.5Bi0.5TiO3)(1−x)(BiCrO3)
x
solid solution. XAS measurements reveal that chromium ion occupies the octahedral site in Na0.5Bi0.5TiO3 (NBT). The increase in chromium content increases the distortion in chromium-oxygen octahedral. No shift in the Cr–K edge
was observed with increase in chromium content. The XAS measurements suggest that chromium exists either as +3 or +5 state
in (Na0.5Bi0.5TiO3)(1−x)(BiCrO3)
x
. The impedance measurements show a considerable increase in the electrical conductivity with increase in chromium content.
The activation energy for conduction mechanism was found to lie between 0.50 and 0.7 eV for all the samples. These measurements
indicate that main contribution to the conductivity is because of oxygen defects generated by the incorporation of chromium
at B-site of NBT. 相似文献
18.
Effects of Ga content on thermoelectric properties of P-type Ba8Ga16+ x Zn3Ge27? x type-I clathrates
P-type Ba8Ga16+x
Zn3Ge27−x
(x = 0.1, 0.2, 0.3, and 0.4) type-I clathrates were synthesized by combining solid-state reaction with spark plasma sintering
(SPS) technology. The effects of slight increase of Ga content on thermoelectric properties have been investigated. The results
show that at room temperature the carrier concentration N
p of p-type Ba8Ga16+x
Zn3Ge27−x
clathrates increases remarkably compared with that of Ba8Ga16Zn3Ge27 compound, which results in the increases of electrical conductivity although carrier mobility μ
H slightly decreases. The thermal conductivity κ of all samples increases with the increase of Ga content. Ba8Ga16.2Zn3Ge26.8 compound exhibits the highest ZT value of 0.43 at 700 K, which is increased by 13% compared with that of Ba8Ga16Zn3Ge27 compound. 相似文献
19.
X-ray diffraction (XRD) and the X-ray photoelectron spectroscopy (XPS) were measured for the sintered BSCF ceramics (Ba0.5Sr0.5Co
x
Fe1−x
O3−δ, x = 0.2 and 0.8: BSCF5528 and BSCF5582, respectively), which were annealed at different temperatures (700 and 950 °C) and gases
(O2 and Ar). The unit cell of the annealed BSCF5528 at 950 °C under Ar expanded by 0.8%, while contracting by 0.45% under O2. The cubic and rhombohedral phases coexist in the BSCF5582 annealed at 700 °C under O2. The XPS peak areas of lattice oxygen (O2−) in O1s
, ~528 eV, and the shoulder peak of Co2p
/Ba3d
in BSCF5582 (~778 eV) increased significantly after being annealed in O2. The areas of the peaks for BaCO3 (87.9/90.2 eV) in Ba4d
preferentially were shown to decrease in Ar and increase in O2. 相似文献
20.
F. M. M. Pereira C. A. R. Junior M. R. P. Santos R. S. T. M. Sohn F. N. A. Freire J. M. Sasaki J. A. C. de Paiva A. S. B. Sombra 《Journal of Materials Science: Materials in Electronics》2008,19(7):627-638
The M-type barium hexaferrite Ba
x
Sr1−x
Fe12O19 (where 0 < x < 1) alloys were prepared by a new ceramic procedure. The samples were studied using X-ray diffraction and Rietveld analysis,
scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, infrared and M?ssbauer spectroscopy. The X-ray analysis
indicates that the all the samples present a hexagonal structure. The IR spectra showed three main absorption bands in range
of 400–600 cm−1 corresponding to SFO100 and BFO100. The M?ssbauer spectra showed a superposition of five subspectra associated with the five
sites of the iron ion, which in the ferric state. The SEM studies showed that the hexaferrites presented grains that varied
in the range of 260–305 nm. The dielectric properties: dielectric constant (ε′) and dielectric loss (tg δ) were measured at room temperature in the frequency range from 100 Hz to 40 MHz. The samples present a nonlinear behavior
for the dielectric constant at 100 Hz, 1 kHz and 1 MHz. The dielectric constant is not following the linear mixing rule for
the samples. The structural, dielectric and magnetic properties of the composite barium hexaferrite phases were discussed
in view of applications as a material for permanent magnets, high density magnetic recording and microwave devices. 相似文献