Growth of AlBN Solid Solution by OMVPE

1996 ◽  
Vol 449 ◽  
Author(s):  
M. Shin ◽  
A. Y. Polyakov ◽  
W. Qian ◽  
M. Skowronski ◽  
D. W. Greve ◽  
...  

ABSTRACTLayers of AIBN were grown on sapphire by organometallic vapor phase epitaxy (OMVPE) at 1050°C using triethylboron (TEB), trimethylaluminum (TMA) and ammonia as precursors. Boron is readily incorporated into the layers and its concentration in the solid phase can be made fairly high, up to at least 40%. However, single phase AIxB1–xN films can only be grown for compositions not exceeding x=0.01. For higher B concentrations a second B-rich phase is formed. This phase is shown to be most probably wurtzite BN based on the results of transmission electron microscopy and x-ray diffraction. The growth of this phase occurs within the framework of wurtzite AIN islands providing the sites for lateral growth of wurtzite BN. This leads to formation of columnar structure of AIN and BN crystallites oriented in the basal plane and existing side by side. This is one of the first observation of purely thermal growth of sp3 bonded BN.

2017 ◽  
Vol 898 ◽  
pp. 1669-1674 ◽  
Author(s):  
Bin Shao ◽  
Bing Bing Li ◽  
Chun Hong Li ◽  
Yi Long Ma ◽  
Qiang Zheng ◽  
...  

The microstructure and the chemistry distribution of AlNiCo 9 samples were characterized by the X-ray diffraction, magnetic force microscope, field emission scanning electron microscopy and transmission electron microscope. An interface of a high Al content was formed near the FeCo-rich phases with a size of about 30 nm. S elements mainly combined with Ti to form titanium sulfide bars with the length between 70-150 μm, while S elements was not confirmed in the nanostructured FeCo-rich phase and AlNi-rich phase. Si and Nb preferably existed in the NiAl-rich phase, and a higher content Nb near the Cu precipitate boundary was observed. Moreover, the magnetic domain structure of AlNiCo 9 was also studied.


2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.


1992 ◽  
Vol 280 ◽  
Author(s):  
Z. Ma ◽  
L. H. Allen

ABSTRACTSolid phase epitaxial (SPE) growth of SixGei1-x alloys on Si (100) was achieved by thermal annealing a-Ge/Au bilayers deposited on single crystal Si substrate in the temperature range of 280°C to 310°C. Growth dynamics was investigated using X-ray diffraction, Rutherford backscattering spectrometry, and cross-sectional transmission electron microscopy. Upon annealing, Ge atoms migrate along the grain boundaries of polycrystalline Au and the epitaxial growth initiates at localized triple points between two Au grains and Si substrate, simultaneously incorporating a small amount of Si dissolved in Au. The Au is gradually displaced into the top Ge layer. Individual single crystal SixGei1-x islands then grow laterally as well as vertically. Finally, the islands coalesce to form a uniform layer of epitaxial SixGe1-x alloy on the Si substrate. The amount of Si incorporated in the final epitaxial film was found to be dependent upon the annealing temperature.


2013 ◽  
Vol 802 ◽  
pp. 227-231
Author(s):  
Panida Pilasuta ◽  
Pennapa Muthitamongkol ◽  
Chanchana Thanachayanont ◽  
Tosawat Seetawan

Crystal structure of Zn0.96Al0.02Ga0.02O was analyzed by X-Ray diffraction (XRD) technique and the microstructure was observed by scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD results showed single phase and hexagonal structure a = b = 3.24982 Å, and c = 5.20661 Å. The SEM and TEM results showed the grain size of material arrangement changed after sintering and TEM diffraction pattern confirmed hexagonal crystal structure of Zn0.96Al0.02Ga0.02O after sintering.


2004 ◽  
Vol 19 (4) ◽  
pp. 1093-1104 ◽  
Author(s):  
Q. Luo ◽  
D.B. Lewis ◽  
P.Eh. Hovsepian ◽  
W-D. Münz

Cubic NaCl-B1 structured multilayer TiAlN/VN with a bi-layer thickness of approximately 3 nm and atomic ratios of (Ti+Al)/V = 0.98 to 1.15 and Ti/V = 0.55 to 0.61 were deposited by unbalanced magnetron sputtering at substrate bias voltages between -75 and -150 V. In this paper, detailed transmission electron microscopy and x-ray diffraction revealed pronounced microstructure changes depending on the bias. At the bias -75 V, TiAlN/VN followed a layer growth model led by a strong (110) texture to form a T-type structure in the Thornton structure model of thin films, which resulted in a rough growth front, dense columnar structure with inter-column voids, and low compressive stress of -3.8 GPa. At higher biases, the coatings showed a typical Type-II structure following the strain energy growth model, characterized by the columnar structure, void-free column boundaries, smooth surface, a predominant (111) texture, and high residual stresses between -8 and -11.5 GPa.


2006 ◽  
Vol 16 (01n02) ◽  
pp. 127-136
Author(s):  
P. MALAR ◽  
TAPASH RANJAN RAUTRAY ◽  
V. VIJAYAN ◽  
S. KASIVISWANATHAN

Polycrystalline ingots of CuInSe 2 and CuIn 3 Se 5 were synthesized by melt-quench technique starting from the stoichiometric mixture of constituent elements. X-ray Diffraction (XRD) studies confirmed the single-phase nature of the materials. Compositional analysis by Particle Induced X-ray Emission (PIXE) showed that the compounds are near stoichiometric. Thin films of CuInSe 2 and CuIn 3 Se 5 were grown from pre-synthesized CuInSe 2 and CuIn 3 Se 5 powders. The films were polycrystalline, single-phase and near stoichiometric in nature, as indicated by Transmission Electron Microscopy (TEM) and PIXE studies.


2008 ◽  
Vol 23 (11) ◽  
pp. 2880-2885 ◽  
Author(s):  
Herbert Willmann ◽  
Paul H. Mayrhofer ◽  
Lars Hultman ◽  
Christian Mitterer

Microstructure and hardness evolution of arc-evaporated single-phase cubic Al0.56Cr0.44N and Al0.68Cr0.32N coatings have been investigated after thermal treatment in Ar atmosphere. Based on a combination of differential scanning calorimetry and x-ray diffraction studies, we can conclude that Al0.56Cr0.44N undergoes only small structural changes without any decomposition for annealing temperatures Ta ⩽ 900 °C. Consequently, the hardness decreases only marginally from the as-deposited value of 30.0 ± 1.1 GPa to 29.4 ± 0.9 GPa with Ta increasing to 900 °C, respectively. The film with higher Al content (Al0.68Cr0.32N) exhibits formation of hexagonal (h) AlN at Ta ⩾ 700 °C, which occurs preferably at grain boundaries as identified by analytical transmission electron microscopy. Hence, the hardness increases from the as-deposited value of 30.1 ± 1.3 GPa to 31.6 ± 1.4 GPa with Ta = 725 °C. At higher temperatures, where the size and volume fraction of the h-AlN phase increases, the hardness decreases to 27.5 ± 1.0 GPa with Ta = 900 °C.


2012 ◽  
Vol 02 (01) ◽  
pp. 1250007 ◽  
Author(s):  
LAXMAN SINGH ◽  
U. S. RAI ◽  
K. D. MANDAL ◽  
MADHU YASHPAL

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.


1997 ◽  
Vol 482 ◽  
Author(s):  
E. L. Piner ◽  
N. A. El-Masry ◽  
S. X. Liu ◽  
S. M. Bedair

AbstractInGaN films in the 0–50% InN composition range have been analyzed for the occurrence of phase separation. The ñ0.5 jum thick InGaN films were grown by metalorganic chemical vapor deposition (MOCVD) in the 690 to 780°C temperature range and analyzed by θ−20 x-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area diffraction (SAD). As-grown films with up to 21% InN were single phase. However, for films with 28% InN and higher, the samples showed a spinodally decomposed microstructure as confirmed by TEM and extra spots in SAD patterns that corresponded to multiphase InGaN. An explanation of the data based on the GaN-InN pseudo-binary phase diagram is discussed.


2009 ◽  
Vol 24 (8) ◽  
pp. 2483-2498 ◽  
Author(s):  
Axel Flink ◽  
Manfred Beckers ◽  
Jacob Sjölén ◽  
Tommy Larsson ◽  
Slawomir Braun ◽  
...  

(Ti1–xSix)Ny (0 ≤ x ≤ 0.20; 0.99 ≤ y(x) ≤ 1.13) thin films deposited by arc evaporation have been investigated by analytical transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and nanoindentation. Films with x ≤ 0.09 are single-phase cubic (Ti,Si)N solid solutions with a dense columnar microstructure. Films with x > 0.09 have a featherlike microstructure consisting of cubic TiN:Si nanocrystallite bundles separated by metastable SiNz with coherent-to-semicoherent interfaces and a dislocation density of as much as 1014 cm−2 is present. The films exhibit retained composition and hardness between 31 and 42 GPa in annealing experiments to 1000 °C due to segregation of SiNz to the grain boundaries. During annealing at 1100–1200 °C, this tissue phase thickens and transforms to amorphous SiNz. At the same time, Si and N diffuse out of the films via the grain boundaries and TiN recrystallize.


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