共查询到20条相似文献,搜索用时 46 毫秒
1.
Doreen D. Edwards Pollyanna E. Folkins Thomas O. Mason 《Journal of the American Ceramic Society》1997,80(1):253-257
Subsolidus phase relationships in the Ga2 O3 –In2 O3 system were studied by X-ray diffraction and electron probe microanalysis (EPMA) for the temperature range of 800°–1400°C. The solubility limit of In2 O3 in the β-gallia structure decreases with increasing temperature from 44.1 ± 0.5 mol% at 1000°C to 41.4 ± 0.5 mol% at 1400°C. The solubility limit of Ga2 O3 in cubic In2 O3 increases with temperature from 4.X ± 0.5 mol% at 1000°C to 10.0 ± 0.5 mol% at 1400°C. The previously reported transparent conducting oxide phase in the Ga-In-O system cannot be GaInO3 , which is not stable, but is likely the In-doped β-Ga2 O3 solid solution. 相似文献
2.
Subsolidus phase relationships in the Ga2 O3 –Al2 O3 –TiO2 system at 1400°C were studied using X-ray diffraction. Phases present in the pseudoternary system include TiO2 (rutile), Ga2−2 x Al2 x O3 ( x ≤0.78 β-gallia structure), Al2−2 y Ga2 y O3 ( y ≤0.12 corundum structure), Ga2−2 x Al2 x TiO5 (0≤ x ≤1 pseudobrookite structure), and several β-gallia rutile intergrowths that can be expressed as Ga4−4 x Al4 x Ti n −4 O2 n −2 ( x ≤0.3, 15≤ n ≤33). This study showed no evidence to confirm that aluminum substitution of gallium stabilizes the n =7 β-gallia–rutile intergrowth as has been mentioned in previous work. 相似文献
3.
Yusuke Kaminaga Hisanori Yamane Takahiro Yamada 《Journal of the American Ceramic Society》2007,90(6):1917-1920
Compounds in a CaO–Y2 O3 –SnO2 system were prepared by a solid-state reaction at 1673 K. The phase relation in this system was investigated by powder X-ray diffraction. Besides the previously reported ternary compounds, CaSnO3 , Ca2 SnO4 , Y2 Sn2 O7 , and a quaternary compound Ca0.4 Y1.2 Sn0.4 O3 , solid-solution series of Ca2− x Y2 x Sn1− x O4 with 0≤ x ≤0.5, and Ca1− y Y2 y Sn1− y O3 with 0≤ y ≤0.2 and 0.95≤ y ≤1.0 were found. The cell parameters of these solid-solution series were refined. The changes of rhombohedral cell parameters in the samples prepared in the range 0.565< y <0.714 of Ca1− y Y2 y Sn1− y O3 suggested the existence of solid solutions of Ca0.4 Y1.2 Sn0.4 O3 , although their single phases could not be prepared, except at y =0.6. 相似文献
4.
Daniel R. Kammler Bryan J. Harder Nikolas W. Hrabe Nikkia M. McDonald Gabriela B. González David A. Penake Thomas O. Mason 《Journal of the American Ceramic Society》2002,85(9):2345-2352
Subsolidus phase relations have been determined in the CdO–InO1.5 –SnO2 system at 1175°C. A cubic-bixbyite solution In2−2 x (Cd,Sn)2 x O3 (0 < x < 0.34), a cubic spinel solution (1− x )CdIn2 O4 – x Cd2 SnO4 (0 < x < 0.75), and an orthorhombic-perovskite solution Cd1− x Sn1− x In2 x O3 (0 < x < 0.045) having the GdFeO3 structure have been discovered. The CdO phase field exists over a small range of InO1.5 (<3%) and SnO2 (<1%). Orthorhombic Cd2 SnO4 (Sr2 PbO4 structure) and rutile SnO2 appear to be point compounds with negligible solubility. The vertical section between spinel CdIn2 O4 and orthorhombic Cd2 SnO4 was determined between 900° and 1175°C. The spinel phase field (1− x )CdIn2 O4 – x Cd2 SnO4 was found to extend between x = 0 and x = 0.75 at 1175°C or x = 0.78 at 900°C. All of the phases in this system appear to allow small excess quantities of the donors In and/or Sn (vs cation stoichiometry) which may be the source of the electrons that give these oxides their n-type character. The electrical and optical properties of bulk and thin-film specimens in this system are compared and contrasted with each other and the relative merits of each are assessed. 相似文献
5.
Wei Zheng Xiaofeng Lu Wei Wang Bo Dong Hongnan Zhang Zhaojie Wang Xiuru Xu Ce Wang 《Journal of the American Ceramic Society》2010,93(1):15-17
In this paper, we presented a simple and effective electrospinning technique for the preparation of In2 O3 –SnO2 composite nanofibers. The morphology and chemical structure of the as-prepared samples were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results showed that large quantities of In2 O3 –SnO2 composite nanofibers with diameters from 60 to 100 nm were obtained. The In2 O3 –SnO2 composite nanofibers exhibited excellent gas sensing properties to methanol, such as fast response/recovery properties, high sensitivity, and good selectivity. 相似文献
6.
Activities of NiO were measured in the oxide and spinel solutions of the system MnO–NiO–Al2 O3 at 1300° and 1400° C with the aim of deriving information on the thermodynamic properties of the spinel phases. Synthetic samples in selected phase assemblages of the system were equilibrated with metallic nickel and a gas phase of known oxygen partial pressures at a total pressure of 1 atm. The data on NiO activities and directions of conjugation lines between coexisting oxide and spinel phases were used to establish the activity–composition relations in spinel solid solutions at 1300° and 1400°C. The MnAl2 O4 –NiAl2 O4 solid solutions exhibit considerable negative deviations from ideality at these temperatures. The free energy of formation of MnAl2 O4 from its oxide components (MnO + Al2 O3 ) at 1300° and 1400°C is calculated to be −24.97 and −26.56 kJ. mol−1 , respectively. The activities determined in the stoichiometric spinel solid solutions are more negative as compared with those predicted from cation distribution models. 相似文献
7.
Phase relations within the "V2 O3 –FeO" and V2 O3 –TiO2 oxide systems were determined using the quench technique. Experimental conditions were as follows: partial oxygen pressures of 3.02 × 10−10 , 2.99 × 10−9 , and 2.31 × 10−8 atm at 1400°, 1500°, and 1600°C, respectively. Analysis techniques that were used to determine the phase relations within the reacted samples included X-ray diffractometry, electron probe microanalysis (energy-dispersive spectroscopy and wavelength-dispersive spectroscopy), and optical microscopy. The solid-solution phases M2 O3 , M3 O5 , and higher Magneli phases (M n O2 n −1 , where M = V, Ti) were identified in the V2 O3 –TiO2 system. In the "V2 O3 –FeO" system, the solid-solution phases M2 O3 and M3 O4 (where M = V, Ti), as well as liquid, were identified. 相似文献
8.
Anita Fossdal Mari-Ann Einarsrud Tor Grande 《Journal of the American Ceramic Society》2005,88(7):1988-1991
The phase relations in the pseudo-ternary system La2 O3 –SrO–Fe2 O3 have been investigated in air. Isothermal sections at 1100° and 1300°C are presented based on X-ray diffraction and thermal analysis of annealed samples. Extended solid solubility was observed for the compounds Sr n +1− v La v Fe n O3 n +1−δ ( n =1, 2, 3, and ∞) and Sr1− x La x Fe12 O19 , while only limited solubility of La in Sr4− z La z Fe6 O13±δ was observed. At high Fe2 O3 content, a liquid with low La2 O3 content was stable at 1300°C. 相似文献
9.
Hiroyuki Ikawa Hiromasa Shimojima Kazuyori Urabe Osamu Fukunaga 《Journal of the American Ceramic Society》1991,74(8):1899-1904
Axial and dilatometric thermal expansions and phase transformations were studied for solid solutions having the α-PbO2 structure in the ZrTiO4 —In2 O3 —M2 O5 (M = Sb, Ta) system with nominal formulas of Zr x Ti y In z Sb z O4 and Zr x Ti y In z Ta z O4 where x + y + 2 z = 2. With increased substitution of z , the cell volume increased, the difference in the b parameters at room temperature between those quenched from 1400° and 1000°C decreased, and the thermal expansion decreased. The axial thermal expansion of ZrTi y In z · Ta z O4 with z = 0.3 was almost identical with that of HfTiO4 , and those with z = 0.4 and z = 0.45 were smaller than that of HfTiO4 . Unit-cell volumes of these compound were compared with those of single oxides to make it clear that the unit-cell volume of ZrTiO4 was small anomalously and to distinguish the normal and abnormal substitution systems. These results were explained by the working hypothesis proposed for these compounds. 相似文献
10.
Donald B. Dingwell 《Journal of the American Ceramic Society》1992,75(6):1656-1657
11.
Phase relations and lattice constants in the MgO–Al2 O3 –Ga2 O3 system at 1550°C have been determined experimentally. In a large part of this system, only a nonstoichiometric spinel is stable. Compositions as extreme as 12.5 mol% MgO–20.5 mol% Ga2 O3 –67 mol% Al2 O3 for a homogeneous spinel are possible. In the bordering phase diagrams of MgO–Al2 O3 and MgO–Ga2 O3 , the composition of the spinel is as high as 63 mol% Al2 O3 or Ga2 O3 , respectively. The contributions of all simple ionic exchange reactions on the lattice constant of the spinel have been deduced from X-ray diffractometry data. 相似文献
12.
Tsuyoshi Honma Yasuhiko Benino Takumi Fujiwara Takayuki Komatsu Ryuji Sato 《Journal of the American Ceramic Society》2005,88(4):989-992
The glass formation region, crystalline phases, second harmonic (SH) generation, and Nd:yttrium aluminum garnet (YAG) laser-induced crystallization in the Sm2 O3 –Bi2 O3 –B2 O3 system were clarified. The crystalline phases of Bi4 B2 O9 , Bi3 B5 O12 , BiBO3 , Sm x Bi1− x BO3 , and SmB3 O6 were formed through the usual crystallization in an electric furnace. The crystallized glasses consisting of BiBO3 and Sm x Bi1− x BO3 showed SH generations. The formation of the nonlinear optical BiB3 O6 phase was not confirmed. The formation (writing) region of crystal lines consisting of Sm x Bi1− x BO3 by YAG laser irradiation was determined, in which Sm2 O3 contents were∼10 mol%. The present study demonstrates that Sm2 O3 –Bi2 O3 –B2 O3 glasses are promising materials for optical functional applications. 相似文献
13.
CaO and Ga2 O3 form three compounds: 3CaO-Ga2 O3 , CaO-Ga2 O3 , and CaO-2Ga2 O3 . 3CaO-Ga2 O3 melts incongruently to CaO plus liquid at 1263°C.; CaO Ga2 O3 and CaO 2Ga2 O3 melt congruently at 1369° and 1504°C. respectively. Eutectics are located at the following temperatures and compositions (in mole% Ga2 O3 ): between 3CaO Ga2 O3 and CaO Ga2 O3 , 1245°C. and 37.5%; between CaO Ga2 O3 and CaO-2Ga2 O3 ,1323o C. and 57.0%; and between CaO -2Ga2 O3 and β-Ga2 O3 ,1457°C. and 68.0%. There is a peritectic at 1263°C. and 36.0%. Three polymorphs of CaO Ga2 O3 are described. Compositions from approximately 35 to 70 mole% Ga2 O3 can be quenched to yield homogeneous glasses. 相似文献
14.
The quenching method has been used to determine approximate phase relations in the system iron oxide-Cr2 O3 in air. Only two crystalline phases, a sesquioxide solid solution (Fe2 O3 –Cr2 O3 ) with corundum structure and a spinel solid solution (approximately FeO ·Fe2 O3 –FeO – Cr2 O3 ), occur in this system at conditions of temperature and O2 partial pressure (0.21 atm.) used in this investigation. Liquidus temperatures increase rapidly as Cr2 O3 is added to iron oxide, from 1591°C. for the pure iron oxide end member to a maximum of approximately 2265°C. for Cr2 O3 . Spinel(ss) is the primary crystalline phase in iron oxide-rich mixtures and sesquioxide (ss) in Cr2 O3 –rich mixtures. These two crystalline phases are present together in equilibrium with a liquid and gas (po2 = 0.21 atm.) at approximately 2075°C. 相似文献
15.
Two cubic pyrochlore phases exist in the system ZnO–Bi2 O3 –Sb2 O5 . Neither has the supposed "ideal" stoichiometry, Zn2 Bi3 Sb3 O14 . One, P 1 , is a solid solution phase, Zn2+ x Bi2.96−( x − y ) Sb3.04− y O14.04+δ where 0< x <0.13(1), 0< y <0.017(2) and a =10.4285(9)−10.451(1) Å. The other, P 2 , is a line phase, Zn2 Bi3.08 Sb2.92 O13.92 with a =10.462(2) Å. Subsolidus phase relations at 950°C involving phases P 1 and P 2 in the ZnO–Bi2 O3 –Sb2 O5 phase diagram have been determined. 相似文献
16.
The monolithic glass-forming region of the low phonon and low softening point antimony glasses containing high Sb2 O3 (40–75 mol%) in the novel quaternary K2 O–B2 O3 –Sb2 O3 –ZnO system has been found with the help of X-ray diffraction (XRD) analysis. The structure of a series of glasses with the general composition of (mol%) 15K2 O–15B2 O3 –(70− x )Sb2 O3 – x ZnO (where x =5–25) has been evaluated by infrared reflection spectral (FT-IRRS) analyses. All the glasses are found to possess a low phonon energy of around 600 cm−1 , as revealed by FT-IRRS. Their softening point ( T s ), glass transition temperature ( T g ), and coefficient of thermal expansion (CTE) have been found to vary in the ranges of 351°–379°C, 252°–273°C, and 195–218 × 10−7 K−1 , respectively. These properties are found to be controlled by their fundamental property, like the covalent character of the glasses, which is found to increase with an increase in Sb2 O3 content. In addition, the devitrified glasses have been characterized by XRD and field emission scanning electron microscopy, which manifests the presence of nanozinc antimony oxide crystals with sizes of 21–43 nm. The exhibited properties have revealed that they are a new class of versatile materials. 相似文献
17.
Yinsheng Xu Guang Yang Wei Wang Huidan Zeng Xianghua Zhang Guorong Chen 《Journal of the American Ceramic Society》2008,91(3):902-905
The glass-forming region of the GeSe2 –In2 Se3 –CsI system was reported firstly. The dependence of glass properties on compositions as formulas of (1−2 x )GeSe2 − x (In2 Se3 –CsI) and (0.8− x )GeSe2 −0.2In2 Se3 − x CsI was investigated. Properties measurements include density, DTA, Raman spectra, visible and near infrared, and infrared (IR) transmission spectra. Raman spectra show that [GeSe4/2 ] and [InSe4− x I x ] tetrahedra are the main structural units in the network of the present glass system. Glasses show larger density (4.29–4.51 g/cm3 ), wider optical transmission window from 0.56 to 16 μm, and higher thermal stability characterized by the bigger Δ T (Δ T = T x – T g >110°C), which make them the promising candidate materials for IR optics. 相似文献
18.
Adam J. G. Ellison Paul C. Hess Gerald C. Naski 《Journal of the American Ceramic Society》1998,81(12):3215-3220
The saturation surface of cassiterite, SnO2 , was determined for liquids in the system K2 O–Al2 O3 –SiO2 as a function of bulk composition and temperature. At fixed K2 O/Al2 O3 cassiterite solubility varies weakly with SiO2 concentration (76 to 84 mol%), temperature (1350° to 1550°C), and log ( f O 2 ) (−0.7 to −5.3). Cassiterite solubility is also approximately independent of composition in liquids with molar ratios of K2 O/Al2 O3 lessthan equal to 1 (peraluminous liquids). As K2 O/Al2 O3 increases from 1 (peralkaline liquids), however, cassiterite solubility increases steeply and approximately linearly with K2 O in excess of Al2 O3 . It is proposed that potassium in excess of aluminum combines with Sn4+ to form quasi-molecular complexes with an effective stoichiometry of K4 SnO4 . 相似文献
19.
Zirconia-rich subsolidus phase relationships in the ZrO2 –Sc2 O3 and ZrO2 –In2 O3 systems were investigated. Phase inconsistencies in the ZrO2 –Sc2 O3 system resulted from a diffusionless cubic-to-tetragonal ( t' ) phase transformation not being recognized in the past. Through three different measuring techniques, along with microstructural observations, the solubility limits of the tetragonal and cubic phases were determined. 相似文献
20.
Toshiya Hirata 《Journal of the American Ceramic Society》2000,83(12):3205-3207
Based on the virtual crystal approximation (or Vegard's law), the bond lengths of Ti1− x Sn x O2 were deduced from those of TiO2 and SnO2 , to allow the oxygen position and octahedral distortion to be determined as a function of x . The oxygen positional parameter ( u ) increased linearly when the Sn4+ cation (which has a larger ionic radius) was substituted for the Ti4+ cation, whereas the octahedral distortion exhibited a nonlinear decay with increasing x in Ti1− x Sn x O2 . At the same time, the bond-valence parameter, which relates bond valence to bond length, so that the central atom in the octahedron can retain a constant valence of +4.0, exhibited a correlation with u for Ti1− x Sn x O2 . The present results indicate that the different phonon/physical properties of TiO2 and SnO2 and/or their dependence on x in Ti1− x Sn x O2 can be associated with different octahedral distortions. 相似文献