High Temperature X-Ray Diffraction Study of PbTio3 Thin Films Grown on Mgo(001) by MOCVD

1995 ◽  
Vol 415 ◽  
Author(s):  
R.S. Batzer ◽  
Biming Yen ◽  
Donhang Liu ◽  
H. Kubo ◽  
G.R. Bai ◽  
...  

ABSTRACTLead titanate (PT) is ferroelectric in its tetragonal phase (c/a=1.06). The domain formation is coupled to the relaxation of internal stress generated by a combination of lattice mismatch, transformation strain and differential thermal stress. The mechanism of domain formation in an epitaxially grown PT film is related to the substrate type and the growth temperature. In this study, PT films have been deposited on MgO(001) in a coldwall, horizontal metal organic chemical vapor deposition (MOCVD) system. The structure of domains and their evolution have been measured as a function of temperature by the x-ray diffraction method using a hot stage. Domain structure changes were observed by θ−2θ scans, ω scans, as well as in-plane φ scans. Effect of film stress on the ferroelectric transition temperature is discussed. Reproducibility of domain formation as a result of temperature cycling both below and above Tc is assessed.

1999 ◽  
Vol 595 ◽  
Author(s):  
M.L. Caldwell ◽  
H.H. Richardson ◽  
M.E. Kordesch

AbstractAn aluminum nitride (AlN) film deposited on silicon (100) was used as the substrate for growing manganese (Mn) doped AlN film by metal organic chemical vapor deposition (MOVCD). The (15.78 [.proportional]m) under layer of AlN was grown at 615°C at a pressure of 10−4 Torr. The (2.1 [.proportional]m) top layer of Mn-AlN was grown at the same temperature and pressure but doped with pulse valve introduction of the manganese decacarbonyl (100 ms on, 100 ms off). The film was then characterized ex situ with IR reflectance microscopy, X-ray diffraction, scanning electron microscopy imaging, cathodoluminescence, and X-ray fluorescence. The IR reflectance measurements showed a strong (A1) LO mode for AlN at 920 cm−1 and 900 cm−1 with a shoulder at 849 cm−1. X-ray Diffraction yielded three diffraction peaks at a 2ø position of 33, 36 and 38 degrees corresponding to 100, 002, and 101 lattice planes respectively. Cathodoluminescence results show strong visible emitted light from incorporated manganese. The relative percentage of manganese to aluminum was below the detection limit (0.01 %) of the Xray fluorescence spectrometer. Amorphous Mn doped AlN films have also been grown using a low temperature atomically abrupt sputter epitaxial system. The amorphous Mn doped AlN showed no cathodoluminescence.


2009 ◽  
Vol 421-422 ◽  
pp. 135-138
Author(s):  
Ken Nishida ◽  
Minoru Osada ◽  
Shintaro Yokoyama ◽  
Takafumi Kamo ◽  
Takashi Fujisawa ◽  
...  

Micro-patterned Pb(Zr,Ti)O3 (PZT) films with dot-pattern were grown by metal organic chemical vapor phase deposition (MOCVD). Micro-patterned Pb(Zr,Ti)O3 (PZT) films were formed on dot-patterned SrRuO3 (SRO) buffer layer that was prepared by MOCVD through the metal mask on (111)Pt/Ti/SiO2/Si substrate. The orientation of dot-patterned PZT films was ascertained by the micro-beam x-ray diffraction (XRD) and their crystallinity was characterized by Raman spectroscopy. It was found that PZT films were oriented to (111) on dot-pattern, while (100)/(001) out of dot-pattern and the amount of oxygen vacancies at the circumference of the dot-pattern were larger than that of center of dot-pattern.


2022 ◽  
Vol 43 (1) ◽  
pp. 012303
Author(s):  
Xiujun Hao ◽  
Yan Teng ◽  
He Zhu ◽  
Jiafeng Liu ◽  
Hong Zhu ◽  
...  

Abstract We demonstrate a high-operating-temperature (HOT) mid-wavelength InAs/GaSb superlattice heterojunction infrared photodetector grown by metal–organic chemical vapor deposition. High crystalline quality and the near-zero lattice mismatch of a InAs/GaSb superlattice on an InAs substrate were evidenced by high-resolution X-ray diffraction. At a bias voltage of –0.1 V and an operating temperature of 200 K, the device exhibited a 50% cutoff wavelength of ~ 4.9 μm, a dark current density of 0.012 A/cm2, and a peak specific detectivity of 2.3 × 109 cm·Hz1/2 /W.


2015 ◽  
Vol 1738 ◽  
Author(s):  
Andrew J. Clayton ◽  
Stuart J. C. Irvine ◽  
Vincent Barrioz ◽  
Alessia Masciullo

ABSTRACTAn inline metal organic chemical vapor deposition system was used to deposit tin sulfide at temperatures >500 °C. Tetramethyltin was used as the tin source and diethyldisulfide as the sulfur source. An overhead injector configuration was used delivering both precursors directly over the substrate. The tin and sulfur precursors were premixed before injection to improve chemical reaction in the gas phase. Growth temperatures 500 – 540 °C were employed producing films with approximate 1:1 stoichiometry of Sn and S detected by energy dispersive x-ray spectroscopy. X-ray diffraction showed there to be mixed phases with Sn2S3 present with SnS.


2004 ◽  
Vol 449-452 ◽  
pp. 205-208
Author(s):  
M. Fujii ◽  
S. Motojima

The double helical carbon micro-coils were obtained by chemical vapor deposition. As-grown carbon micro-coils with amorphous structure were heat-treated at various temperatures up to 3000°C . By heat treatment, the shape of the coils was not changed. The morphology of these coils was observed in detail using electron microscope. The lattice structure was analyzed by X-ray diffraction method. Heat treatment temperature dependence of the magnetoresistance and the measurement of Raman spectra suggest that the coils heattreated at higher temperature are more highly graphitized.


2008 ◽  
Vol 41 (2) ◽  
pp. 272-280 ◽  
Author(s):  
Virginie Chamard ◽  
Julian Stangl ◽  
Stephane Labat ◽  
Bernhard Mandl ◽  
Rainer T. Lechner ◽  
...  

InAs nanowire samples grown by metal-organic chemical vapor deposition present a significant amount of wurtzite structure, while the zincblende lattice is known to be the stable crystal structure for the bulk material. The question of the wurtzite distribution in the sample is addressed using phase-sensitive coherent X-ray diffraction with a micro-focused beam at a synchrotron source. The simultaneous investigation of the wurtzite 10\bar{1}0, 20\bar{2}0 and 30\bar{3}0 reflections performed on a bunch of single wires shows unambiguously that the wurtzite contribution is a result of stacking faults distributed along the wire. Additional simulations lead to adjustments of the wire structural parameters, such as the wurtzite content, the strain distribution, the wire diameters and their respective orientations.


2011 ◽  
Vol 413 ◽  
pp. 11-17 ◽  
Author(s):  
Bin Feng Ding ◽  
Yong Quan Chai

A GaN epilayer with tri-layer AlGaN interlayer grown on Si (111) by metal-organic chemical vapor deposition (MOCVD) method was discussed by synchrotron radiation x-ray diffraction (SRXRD) and Rutherford backscattering (RBS)/C. The crystal quality of the epilayer is very good with a χmin=2.1%. According to the results of the θ-2θ scan of GaN(0002) and GaN(1122), the epilayer elastic strains in perpendicular and parallel directions were calculated respectively to be-0.019% and 0.063%. By the angular scan using RBS/C around a symmetric [0001] axis and an asymmetric [1213] axis in the (1010) plane of the GaN layer, the tetragonal distortion (eT ) were determined to be 0.09%. This result coincides with that from SRXRD perfectly. The strain decreases gradually towards the near-surface layer, which will avoid the film cracks efficiently and improve the crystal quality of the GaN epilayer remarkably.


2008 ◽  
Vol 1068 ◽  
Author(s):  
KungLiang Lin ◽  
Edward-Yi Chang ◽  
Tingkai Li ◽  
Wei-Ching Huang ◽  
Yu-Lin Hsiao ◽  
...  

ABSTRACTGaN film grown on Si substrate with AlN/AlxGa1−xN buffer is studied by low pressure metal organic chemical vapor deposition (MOCVD) method. The AlxGa1−xN film with Al composition varying from 0∼ 0.66 was used. The correlation of the Al composition in the AlxGa1−xN film with the stress of the GaN film grown was studied using high resolution X-ray diffraction including symmetrical and asymmetrical ω/2θscans and reciprocal space maps. It is found that with proper design of the Al composition in the AlxGa1−xN buffer layer, crack-free GaN films can be successfully grown on Si (111) substrates using AlN and AlxGa1−xN buffer layers.


2000 ◽  
Vol 5 (S1) ◽  
pp. 159-166 ◽  
Author(s):  
M.L. Caldwell ◽  
H.H. Richardson ◽  
M.E. Kordesch

An aluminum nitride (AlN) film deposited on silicon (100) was used as the substrate for growing manganese (Mn) doped AlN film by metal organic chemical vapor deposition (MOVCD). The (15.78 µm) under layer of AlN was grown at 615°C at a pressure of 10−4 Torr. The (2.1 µm) top layer of Mn-AlN was grown at the same temperature and pressure but doped with pulse valve introduction of the manganese decacarbonyl (100 ms on, 100 ms off). The film was then characterized ex situ with IR reflectance microscopy, X-ray diffraction, scanning electron microscopy imaging, cathodoluminescence, and X-ray fluorescence. The IR reflectance measurements showed a strong (A1) LO mode for AlN at 920 cm−1 and 900 cm−1 with a shoulder at 849 cm−1. X-ray Diffraction yielded three diffraction peaks at a 2θ position of 33, 36 and 38 degrees corresponding to 100, 002, and 101 lattice planes respectively. Cathodoluminescence results show strong visible emitted light from incorporated manganese. The relative percentage of manganese to aluminum was below the detection limit (0.01 %) of the X-ray fluorescence spectrometer. Amorphous Mn doped AlN films have also been grown using a low temperature atomically abrupt sputter epitaxial system. The amorphous Mn doped AlN showed no cathodoluminescence.


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