scholarly journals Sample chamber for synchrotron based in-situ X-ray diffraction experiments under electric fields and temperatures between 100 K and 1250 K

2021 ◽  
Vol 28 (1) ◽  
pp. 158-168
Author(s):  
Melanie Nentwich ◽  
Tina Weigel ◽  
Carsten Richter ◽  
Hartmut Stöcker ◽  
Erik Mehner ◽  
...  
Keyword(s):  
Electric Fields ◽  
Degrees Of Freedom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating And Cooling ◽  
Hemispherical Dome ◽  
Sample Chamber ◽  
Overall Performance ◽  
Scientific Questions

Many scientific questions require X-ray experiments conducted at varying temperatures, sometimes combined with the application of electric fields. Here, a customized sample chamber developed for beamlines P23 and P24 of PETRA III at DESY to suit these demands is presented. The chamber body consists mainly of standard vacuum parts housing the heater/cooler assembly supplying a temperature range of 100 K to 1250 K and an xyz manipulator holding an electric contact needle for electric measurements at both high voltage and low current. The chamber is closed by an exchangeable hemispherical dome offering all degrees of freedom for single-crystal experiments within one hemisphere of solid angle. The currently available dome materials (PC, PS, PEEK polymers) differ in their absorption and scattering characteristics, with PEEK providing the best overall performance. The article further describes heating and cooling capabilities, electric characteristics, and plans for future upgrades of the chamber. Examples of applications are discussed.

Texture Evolution Under Fast Heating and Cooling Rates of Zirconium Alloys Studied In-Situ by Synchrotron X-Ray Diffraction

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
Cooling Rates ◽  
X Ray ◽  
Heating And Cooling

scholarly journals Pressure-induced Jahn-Teller Switch in the Homoleptic Hybrid Perovskite [(CH3)2NH2]Cu(HCOO)3: Orbital Reordering by Unconventional Degrees of Freedom

2021 ◽  
Author(s):  
Rebecca Scatena ◽  
Michał Andrzejewski ◽  
Roger D Johnson ◽  
Piero Macchi
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Coordination Polymer ◽  
Degrees Of Freedom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hybrid Perovskite ◽  
Jahn Teller

Through in-situ, high-pressure x-ray diffraction experiments we have shown that the homoleptic perovskite-like coordination polymer [(CH3)2NH2]Cu(HCOO)3 undergoes a pressure-induced orbital reordering phase transition above 5.20 GPa. This transition is distinct...

Phase Transitions in Gold Contacts to Gallium Arsenide

1984 ◽  
Vol 37 ◽  
Author(s):  
Edward Beam ◽  
D. D. L. Chung
Keyword(s):  
Gallium Arsenide ◽  
Phase Transitions ◽  
Peritectic Transformation ◽  
Complete Dissolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating And Cooling ◽  
Similar Phase ◽  
Gold Contacts

AbstractX-ray diffraction was used in situ to study the phase transitions which occurred in 1500 Å Au/GaAs(100) upon heating and cooling. The reaction between Au and GaAs took the form Au + Ga → α Au-Ga. Upon heating, α Au-Ga completely dissolved in liquid Au-Ga. Upon subsequent cooling, β Au-Ga (or Au7Ga2) formed. In 1 atm of nitrogen, phase transitions were observed reversibly at 525 ± 25°C (due to the complete dissolution of α Au-Ga upon heating) and 415 ± 5°C (due to the peritectic transformation of β Au-Ga to α Au-Ga and liquid Au-Ga upon heating). In a vacuum of 425 μ (0.031 Kg/2m) similar phase transitions were observed at 425 ± 25°C and 387 ± 13°C, respectively.

scholarly journals Effects of NiO content on the microstructure and mechanical properties of AgSnO2NiO composites

2019 ◽  
Vol 26 (1) ◽  
pp. 221-229 ◽  
Author(s):  
Xiaolong Zhou ◽  
Li Chen ◽  
Manmen Liu ◽  
Jie Yu ◽  
Damin Xiong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Internal Oxidation ◽  
Alloy Powder ◽  
X Ray Diffraction ◽  
Oxidation Method ◽  
X Ray ◽  
Microstructure And Mechanical Properties ◽  
Silver Matrix ◽  
Overall Performance

AbstractThe AgSnO2NiO composites were prepared by internal oxidation method. The effects of different NiO content on the microstructure and mechanical properties of AgSnO2NiO composites were studied. The phase structure and surface morphology of the prepared AgSnO2NiO materials were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Metallographic Microscopy (MM). The results showed that the AgSnO2NiO composites with different NiO content can be obtained by the process of preoxidation of AgSn alloy powder and internal oxidation of ingot containing Ni. The agglomeration phenomenon of Ni in the silver matrix was serious, which led to the agglomeration of in-situ generated NiO particles after internal oxidation. After the multi-pass drawing, the SnO2 particles dispersedly distributed in the AgSnO2NiO composites and the NiO particles gradually dispersed from the agglomerated state of the sintered ingot billet. The hardness of the prepared AgSnO2NiO composites increased slightly with the increase of NiO content. The mechanical properties test showed that the introduction of NiO particles significantly improved the tensile strength and elongation of AgSnO2 materials to a certain degree. Adding proper amount of NiO is beneficial to improve the overall performance of AgSnO2 materials.

scholarly journals In situ x-ray diffraction study of graphitic carbon formed during heating and cooling of amorphous-C/Ni bilayers

2010 ◽  
Vol 96 (15) ◽  
pp. 153105 ◽  
Author(s):  
K. L. Saenger ◽  
J. C. Tsang ◽  
A. A. Bol ◽  
J. O. Chu ◽  
A. Grill ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Graphitic Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating And Cooling

Austenite-Ferrite Transformation in Non-Oriented Electrical Steels

2007 ◽  
Vol 560 ◽  
pp. 85-89
Author(s):  
Enrique Díaz Barriga-Castro ◽  
Armando Salinas-Rodríguez ◽  
Enrique Nava-Vázquez
Keyword(s):  
Electrical Steel ◽  
Tensile Ductility ◽  
X Ray Diffraction ◽  
Electrical Steels ◽  
Transformation Temperatures ◽  
X Ray ◽  
Heating And Cooling ◽  
Ferrite Transformation ◽  
Isothermal Heat Treatments

The aim of the present work is to determine the austenite to ferrite transformation temperatures in a Si-Al non-oriented electrical steel. Critical transformation temperatures on heating and cooling are determined using an in-situ X-ray diffraction technique where the specimen is heated or cooled in a stepwise manner. The transformation temperatures are estimated from changes in the intensities of the (110)α and (111)γ peaks as a function of temperature. The time evolution of the microstructure resulting from isothermal heat treatments at temperatures between 800 and 1000 °C applied after cooling from 1050 °C is followed by quantitative metallography on samples quenched into water. The results show that, on cooling, formation of ferrite starts at about 950 °C and ends at 790 °C, indicating a strong effect of Si and Al on the austenite to ferrite and eutectoid transformations. These results suggest that the low tensile ductility exhibited by this material at temperatures near 1000 °C can be attributed to strain localization in strain-induced ferrite formed at temperatures as high as 1025 °C.

scholarly journals Piezoelectric Properties of Pb1−xLax(Zr0.52Ti0.48)1−x/4O3 Thin Films Studied by In Situ X-ray Diffraction

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3338
Author(s):  
Thomas W. Cornelius ◽  
Cristian Mocuta ◽  
Stéphanie Escoubas ◽  
Luiz R. M. Lima ◽  
Eudes B. Araújo ◽  
...  
Keyword(s):  
Thin Films ◽  
Electric Fields ◽  
Lead Zirconate Titanate ◽  
Piezoelectric Properties ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ac Electric Fields ◽  
Zirconate Titanate

The piezoelectric properties of lanthanum-modified lead zirconate titanate Pb1−xLax(Zr0.52Ti0.48)1−x/4O3 thin films, with x = 0, 3 and 12 mol% La, were studied by in situ synchrotron X-ray diffraction under direct (DC) and alternating (AC) electric fields, with AC frequencies covering more than four orders of magnitude. The Bragg reflections for thin films with low lanthanum concentration exhibit a double-peak structure, indicating two contributions, whereas thin films with 12% La possess a well-defined Bragg peak with a single component. In addition, built-in electric fields are revealed for low La concentrations, while they are absent for thin films with 12% of La. For static and low frequency AC electric fields, all lanthanum-modified lead zirconate titanate thin films exhibit butterfly loops, whereas linear piezoelectric behavior is found for AC frequencies larger than 1 Hz.

TUNABLE PHASE TRANSITION AND PHOTO-INDUCED RESISTANCE IN La0.8Ca0.2MnO3/FERROELECTRIC HETEROSTRUCTURES

2013 ◽  
Vol 27 (22) ◽  
pp. 1350162 ◽  
Author(s):  
J. GAO ◽  
E. J. GUO ◽  
S. Y. WANG ◽  
Z. P. WU ◽  
H. J. BU
Keyword(s):  
Induced Resistance ◽  
Electric Fields ◽  
Piezoelectric Effect ◽  
Perovskite Manganite ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray ◽  
Field Modulation ◽  
Converse Piezoelectric Effect

Heterostructures of La 0.8 Ca 0.2 MnO 3 (LCMO)/ferroelectric were formed by growing a layer of perovskite manganite LCMO on the ferroelectric 0.67 Pb ( Mg 1/3 Nb 2/3) O 3-0.33 PbTiO 3 (PMN-PT) single crystals. Well tunable structural, magnetic, and transport properties were achieved by applying electric fields on the formed heterostructures. By varying electric fields biased on the PMN-PT, the metal–insulator transition and resistance could be modulated continuously and reversely. Field modulation of photo-induced resistance (PR) was also observed. In situ X-ray diffraction indicates that the variation of resistance and PR result from the induced strain due to the coaction ferroelectric polarization or converse piezoelectric effect. The variations of PR under different fields differ significantly when PMN-PT was in positively and negatively polarized states. Such observations could be explained based on the coaction of piezoelectric effect and ferroelectric-field polarization, which subsequently affect the lattice strain and density of charge carrier in the grown LCMO layer.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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