Mechanism of Ca-Ba diffusion in lead-free (Ba,Ca)TiO3 piezoelectrics

2015 ◽  
Vol 1782 ◽  
pp. 23-28 ◽  
Author(s):  
Chang Shu ◽  
Daniel Reed ◽  
Tim Button

AbstractThe reaction mechanism of BaCO3+CaCO3+TiO2 by solid state methods has been studied in this work using thermal analysis (DSC-TG) from 500 to 1500 °C and in situ X-ray diffraction (XRD) from room temperature to 800 °C. In the mixed powders, the CaO is firstly formed followed by presence of an intermediate Ba2TiO4 phase and finally the formation of CaTiO3, BaTiO3 and/or (Ba,Ca)TiO3, where the presence of CaO or CaTiO3 (CT) has slowed down the formation of BaTiO3 (BT). Raman microscopy of a BT-CT diffusion couple has shown that Ca2+ firstly diffuses into the BT grain boundaries and then into the BT core.

2014 ◽  
Vol 70 (12) ◽  
pp. 1138-1142 ◽  
Author(s):  
Le Li ◽  
Jian-Qing Tao

A twofold interpenetrating three-dimensional CdIIcoordination framework, [Cd(C8H3NO6)(C14H14N4)]n, has been prepared and characterized by IR spectroscopy, elemental analysis, thermal analysis and single-crystal X-ray diffraction. The asymmetric unit consists of a divalent CdIIatom, one 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) ligand and one fully deprotonated 5-nitrobenzene-1,3-dicarboxylate (NO2-BDC2−) ligand. The coordination sphere of the CdIIatom consists of five O-donor atoms from three different NO2-BDC2−ligands and two imidazole N-donor atoms from two different 1,3-BMIB ligands, forming a distorted {CdN2O5} pentagonal bipyramid. The NO2-BDC ligand links three CdIIatomsviaa μ1-η1:η1chelating mode and a μ2-η2:η1bridging mode. The title compound is a twofold interpenetrating 3,5-connected network with the {42.65.83}{42.6} topology. In addition, the compound exhibits fluorescence emissions in the solid state at room temperature.


1993 ◽  
Vol 321 ◽  
Author(s):  
W. Dickenscheid ◽  
R. Birringer

ABSTRACTSolid state reactions in mixtures of nanometer-sized Cu and Zr as well as Ni and Zr crystallites -produced by inert-gas condensation followed by in situ compaction - have been investigated by x-ray diffraction and thermal analysis. The annealing behavior is compared to that of corresponding multilayer samples. The results are discussed with emphasis placed on the different parameters controlling solid state reactions.


2009 ◽  
Vol 42 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Zhèn Yáng ◽  
Ashley S. Harvey ◽  
Anna Infortuna ◽  
Ludwig J. Gauckler

Selected compositions of the Ba–Sr–Co–Fe–O system were synthesized from powders by the solid-state reaction method. Samples were equilibrated at 1273 K for 36 000 s in air. The resulting powders were characterized by X-ray diffraction (XRD) at room temperature and by high-temperaturein situXRD. The phases present in the BaxSr1−xCoyFe1−yO3−δsystem are outlined for 1273 K in air. For most of the quaternary compositions, the cubic perovskite is formed, except for the compositions withx= 1 (excludingy= 0.4),y= 1 andx,y= 0.8, where the phases mainly show hexagonal distortions, andx, y= 0, for which a predominant cubic phase is mixed with other phases.


2011 ◽  
Vol 01 (03) ◽  
pp. 345-349 ◽  
Author(s):  
ERIC A. PATTERSON ◽  
DAVID P. CANN

Solid solutions based on Li , Ta and Sb -doped (K0.5Na0.5)NbO3 (KNN) lead-free perovskite systems were created using standard solid-state methods. X-ray diffraction was used to confirm that all compositions were single phase and to verify the phase transition from tetragonal to cubic at TC = 302° C . The three compositions examined, originally developed by Saito and Li , were shown to be strongly ferroelectric with sharp peaks in permittivity present at the Curie temperature. The optimum composition had loss tangent values below 5% up to 100 kHz at room temperature. Bipolar hysteresis measurements showed high values for both maximum polarization (25 and 21 μC/cm2) and remenant polarizations (20 and 16 μC/cm2) for undoped and 0.2 wt% CuO -doped samples. Maximum strain values of greater than 0.23% were observed.


2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.


2016 ◽  
Vol 850 ◽  
pp. 191-196 ◽  
Author(s):  
Wei Wang ◽  
Cun Lei Zou ◽  
Ren Geng Li ◽  
Wen Wen ◽  
Hui Jun Kang ◽  
...  

In situ synchrotron X-ray diffraction was used to study a deformed Cu-0.88 Fe-0.24 P alloy during heating process. The measurements were performed at room temperature and also at high temperatures up to 893 K in order to determine the recovery, ageing and recrystallization process. With the increase of temperature, the angles of copper matrix peaks moved left and the FWHM (full width at half maximum) decreased slightly. Fe3P precipitates were first detected at 533 K, reached the maximum at 673 K, and re-dissolved into matrix at 853 K. A dramatic decrease in FWHM was observed accompanied by the precipitation of Fe3P phases, indicating the reduction of lattice distortion of copper matrix.


2011 ◽  
Vol 21 (15) ◽  
pp. 5604 ◽  
Author(s):  
Zonghai Chen ◽  
Yang Ren ◽  
Yan Qin ◽  
Huiming Wu ◽  
Shengqian Ma ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3920
Author(s):  
Martin Weber ◽  
Gábor Balázs ◽  
Alexander V. Virovets ◽  
Eugenia Peresypkina ◽  
Manfred Scheer

By reacting [{Cp‴Fe(CO)2}2(µ,η1:1-P4)] (1) with in situ generated phosphenium ions [Ph2P][A] ([A]− = [OTf]− = [O3SCF3]−, [PF6]−), a mixture of two main products of the composition [{Cp‴Fe(CO)2}2(µ,η1:1-P5(C6H5)2)][PF6] (2a and 3a) could be identified by extensive 31P NMR spectroscopic studies at 193 K. Compound 3a was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.0]pentaphosphapentane unit. At room temperature, the novel compound [{Cp‴Fe}(µ,η4:1-P5Ph2){Cp‴(CO)2Fe}][PF6] (4) is formed by decarbonylation. Reacting 1 with in situ generated diphenyl arsenium ions gives short-lived intermediates at 193 K which disproportionate at room temperature into tetraphenyldiarsine and [{Cp‴Fe(CO)2}4(µ4,η1:1:1:1-P8)][OTf]2 (5) containing a tetracyclo[3.3.0.02,7.03,6]octaphosphaoctane ligand.


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