SUBSOLIDUS PHASE RELATIONSHIPS AND SUPERCONDUCTIVITY IN Gd2O3-BaO-CuO SYSTEM

1987 ◽  
Vol 01 (02) ◽  
pp. 337-340 ◽  
Author(s):  
Jingkui LIANG ◽  
Xianting Xu ◽  
Guanghui RAO ◽  
Sishen XIE ◽  
Xiuyu SHAO ◽  
...  

The 960°C subsolidus phase relationships in the Gd2O3-BaO-CuO system were determined by means of X-ray diffraction as well as superconductive properties measurements. In the measured partial diagram, two ternary compounds occur: GdBa2Cu3O9−y and Gd2BaCuO5 The relationships between composition and superconductivity were also reported in this paper. Since superconductivity in Ba-Y-Cu-O system was reported(1, 2), many authors have measured the phase diagram for this system (3, 4). In a recent communication we reported superconductivity existing in Ba-Gd-Cu-O system(5). Now we present the results of partial subsolidus phase relationships sintered at 960°C in air, which in turn provide a basis for the sample preparetion technology. We also discussed the effect of compositions on the sintering temperature in this paper.

2002 ◽  
Vol 756 ◽  
Author(s):  
Annette P. Richard ◽  
Doreen D. Edwards

ABSTRACTThe subsolidus phase relationships in the In2O3-WO3 system at 800 – 1400°C were studied by X-ray diffraction. Two binary oxide phases – In2(WO4)3 and In6WO12 – are stable in air over the temperature range of 800 – 1200°C. Preferential volatilization of WO3 prevented the determination of phase equilibria above 1300°C.


2015 ◽  
Vol 655 ◽  
pp. 68-71
Author(s):  
Yuan Yuan Zhu ◽  
Jin Jia ◽  
Ai Guo Zhou ◽  
Li Bo Wang ◽  
Qing Feng Zan

Layered ternary compounds Ti3SiC2combines attractive properties of both ceramics and metals, and has been suggested for potential engineering applications. Near-fully dense Ti3SiC2bulks were sintered from commercial Ti3SiC2powders by hot press at 1350°C-1600°C for 60-120min under Ar atmosphere in this paper. The phase compositions and morphology of the as-prepared samples were evaluated by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). And the mechanical properties were measured by Three-Point bending method. It was found that the Ti3SiC2had only a little of decomposition at sintering temperature above 1350°C. And effects of sintering temperature and holding time on the morphology of the bulk Ti3SiC2are not obvious. Relative density of 98% and flexural strength of 480MPa were obtained for the Ti3SiC2samples sintered at 30MPa and 1400°C for 90min.


1997 ◽  
Vol 52 (10) ◽  
pp. 1169-1174 ◽  
Author(s):  
U. Steiner ◽  
W. Reichelt

The phase diagram of the ternary system Ca/Mo/O has been determined. Powder samples of the ternary compounds CaMoO4, CaMoO3, CaMo5O8, Ca16.5Mo13.5O40 and Ca5.45Mo18O32 were prepared by solid state reactions. Rietveld analysis based on powder X-ray diffraction data shows that the compound CaMo5O8 has monoclinic structure (P21/c) with a = 7.549, b = 9.064, c = 9.974 Å, β = 110.04°. CaMo5O8, Ca16.5Mo13.5O40 and Ca5.45Mo18O32 are semiconductors over the temperature range 75 to 300 K.


2016 ◽  
Vol 52 (1) ◽  
pp. 99-112 ◽  
Author(s):  
J. Zhao ◽  
J. Zhou ◽  
S. Liu ◽  
Y. Du ◽  
S. Tang ◽  
...  

13 ternary Cu-Mg-Si alloys were prepared by means of the powder metallurgy method. Phase equilibria at 500 and 700 oC of the Cu-Mg-Si system were determined using X-ray diffraction analysis (XRD). The existence of 3 ternary compounds in this system was verified: CuMgSi_Sigma (Cu16Mg6Si7), Tau (Cu3Mg2Si), and Laves ((Cu0.8Si0.2)2(Mg0.88Cu0.12)). A thermodynamic modeling for the Cu-Mg-Si system was then conducted on the basis of the experimental data obtained in this work and those critically reviewed from the literature. The complex phase relationship between Laves phase and other phases has been successfully modeled in this work. Comparisons between the calculated and the measured phase diagrams show that most of the experimental data can be reproduced by the presently obtained thermodynamic parameters.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.


Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 313
Author(s):  
Mohamad M. Ahmad ◽  
Hicham Mahfoz Kotb ◽  
Celin Joseph ◽  
Shalendra Kumar ◽  
Adil Alshoaibi

La2/3Cu3Ti4O12 (LCTO) powder has been synthesized by the mechanochemical milling technique. The pelletized powder was conventionally sintered for 10 h at a temperature range of 975–1025 °C, which is a lower temperature process compared to the standard solid-state reaction. X-ray diffraction analysis revealed a cubic phase for the current LCTO ceramics. The grain size of the sintered ceramics was found to increase from 1.5 ± 0.5 to 2.3 ± 0.5 μm with an increase in sintering temperature from 975 to 1025 °C. The impedance results show that the grain conductivity is more than three orders of magnitude larger than the grain boundary conductivity for LCTO ceramics. All the samples showed a giant dielectric constant (1.7 × 103–3.4 × 103) and dielectric loss (0.09–0.17) at 300 K and 10 kHz. The giant dielectric constant of the current samples was attributed to the effect of internal barrier layer capacitances due to their electrically inhomogeneous structure.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.


2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.


1991 ◽  
Vol 46 (5) ◽  
pp. 566-572 ◽  
Author(s):  
Axel Gudat ◽  
Peter Höhn ◽  
Rüdiger Kniep ◽  
Albrecht Rabenau

The isotypic ternary compounds Ba3[MoN4] and Ba3[WN4] were prepared by reaction of the transition metals with barium (Ba3N2, resp.) under nitrogen. The crystal structures were determined by single crystal X-ray diffraction: Ba3[MoN4] (Ba3[WN4]): Pbca; Z = 8; a = 1083.9(3) pm (1091.8(3) pm), b = 1030.3(3) pm (1037.5(3) pm), c = 1202.9(3) pm (1209.2(4) pm). The structures contain isolated tetrahedral anions [MN4]6- (M = Mo, W) which are arranged in form of slightly distorted hexagonal layers and which are stacked along [010] with the sequence (···AB···). Two of the three Ba atoms are situated between, the third one is placed within the layers of [MN4]-groups. In this way the structures can be derived from the Na3As structure type.


2014 ◽  
Vol 1061-1062 ◽  
pp. 83-86
Author(s):  
Hong Wu ◽  
De Yi Zheng

In this paper, the effects of different sintering temperature on the microstructure and piezoelectric properties of Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3(PNZZT) ceramic samples were investigated. The Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3 ceramics materials was prepared by a conventional mixed oxide method. In the period of the experiment, the relationship between crystallographic phase and microstructure were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM) respectively. The XRD patterns shows that all of the ceramic samples are with a tetragonal perovskite structure. Along with sintering temperature increased and the x is 0.03, the grain size gradually become big. Through this experiment, it has been found that when the x is 0.03 and sintered at 1130°C for 2 h, the grains grow well, the grain-boundary intersection of the sample combined well and the porosity of the ceramics decreased, an excellent comprehensive electrical properties of the Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3 samples can be obtained. Its best electrical properties are as follows: dielectric constant (ε) is 1105, dielectric loss(tg) is 0.017, electromechanical coupling coefficient (Kp) is 0.287, piezoelectric constant(d33) is 150PC/N


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