Formation of Face Centered Cubic Titanium Thin Films on MgO(111) Single Crystal Substrate

2018 ◽  
Vol 913 ◽  
pp. 264-269
Author(s):  
Lei Li ◽  
Yan Liu ◽  
Xiao Nan Mao ◽  
Vincent Ji
Keyword(s):  
Single Crystal ◽  
Single Crystal Substrate ◽  
Temperature Phase ◽  
Face Centered Cubic ◽  
Hexagonal Close Packed ◽  
Crystal Substrate ◽  
Cubic Structure ◽  
Hcp Structure ◽  
Face Centered ◽  
Ti Films

High strength, low density, and excellent corrosion resistance are the main properties that make titanium attractive for a variety of applications. The phase structures and phase transitions of titanium, which are of tremendous scientific and technological interest, have attracted a great deal of attention for many years. In addition to hexagonal close packed α-Ti, high temperature phase β-Ti with body-centered cubic structure and ω-Ti with the hexagonal structure of high-pressure phase, the face-centered cubic structure, which is not in the P-T diagram of titanium, is observed in ultrathin films. In the present paper, the Ti films prepared by magnetron sputtering on MgO(111) single crystal substrate were investigated by means of X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscope (HRTEM). The results showed that the Ti films grow epitaxial with a face centered cubic (fcc) structure even the thickness is up to about 50nm. With the thickness increases, the Ti films transformed to hexagonal close packed (hcp) structure and showed an epitaxial growth along (002)hcp-Ti direction. The results show that the onset thickness of fcc-hcp structure transformation is 50-100nm. The temperature and power of sputter affect the formation of fcc-Ti.

Vapor phase dealloying-driven synthesis of bulk nanoporous cobalt with a face-centered cubic structure

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yujun Shi ◽  
Yu Wang ◽  
Wanfeng Yang ◽  
Jingyu Qin ◽  
Qingguo Bai ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Vapor Phase ◽  
Face Centered Cubic ◽  
Hexagonal Close Packed ◽  
Cubic Structure ◽  
Hcp Structure ◽  
Face Centered ◽  
Fcc Structure

Cobalt (Co) mainly exists in two allotropic forms: a low temperature hexagonal close-packed (HCP) structure and a high temperature face centered cubic (FCC) structure. However, annealing at high temperature only...

scholarly journals Stability and equation of state of face-centered cubic and hexagonal close packed phases of argon under pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agnès Dewaele ◽  
Angelika D. Rosa ◽  
Nicolas Guignot ◽  
Denis Andrault ◽  
João Elias F. S. Rodrigues ◽  
...  
Keyword(s):  
Equation Of State ◽  
Single Crystal ◽  
Single Crystal Sample ◽  
Moderate Pressure ◽  
Face Centered Cubic ◽  
Experimental Conditions ◽  
Crystal Sample ◽  
Hexagonal Close Packed ◽  
Face Centered ◽  
Fcc Phase

AbstractThe compression of argon is measured between 10 K and 296 K up to 20 GPa and and up to 114 GPa at 296 K in diamond anvil cells. Three samples conditioning are used: (1) single crystal sample directly compressed between the anvils, (2) powder sample directly compressed between the anvils, (3) single crystal sample compressed in a pressure medium. A partial transformation of the face-centered cubic (fcc) phase to a hexagonal close-packed (hcp) structure is observed above 4.2–13 GPa. Hcp phase forms through stacking faults in fcc-Ar and its amount depends on pressurizing conditions and starting fcc-Ar microstructure. The quasi-hydrostatic equation of state of the fcc phase is well described by a quasi-harmonic Mie–Grüneisen–Debye formalism, with the following 0 K parameters for Rydberg-Vinet equation: $$V_0$$ V 0 = 38.0 Å$$^3$$ 3 /at, $$K_0$$ K 0 = 2.65 GPa, $$K'_0$$ K 0 ′ = 7.423. Under the current experimental conditions, non-hydrostaticity affects measured P–V points mostly at moderate pressure ($$\le$$ ≤ 20 GPa).

Structure of Self-Assembled Fe and FePt Nanoparticle Arrays

2000 ◽  
Vol 636 ◽  
Author(s):  
S. Yamamuro ◽  
D. Farrell ◽  
K. D. Humfeld ◽  
S. A. Majetich
Keyword(s):  
Phase Contrast ◽  
Face Centered Cubic ◽  
Nanoparticle Arrays ◽  
Hexagonal Close Packed ◽  
Transmission Electron ◽  
Self Assembled ◽  
Hcp Structure ◽  
Face Centered ◽  
Contrast Image ◽  
Image Simulations

AbstractArrays were self-assembled by evaporating suspensions of 4 nm FePt or 8 nm Fe nanoparticles. The monolayers had a hexagonal close packed (hcp) structure, but the multilayer structure varied. To identify the multilayer structures, transmission electron microscopy (TEM) images were compared with phase contrast image simulations. The results showed that Fe could be grown as both hcp and face-centered cubic (fcc), or fcc-like, structures. The results of image analysis of the FePt arrays were consistent with fcc structures.

Noble Metal Nanomaterials with Nontraditional Crystal Structures

2020 ◽  
Vol 50 (1) ◽  
pp. 345-370 ◽  
Author(s):  
Chaitali Sow ◽  
Suchithra P ◽  
Gangaiah Mettela ◽  
Giridhar U. Kulkarni
Keyword(s):  
Crystal Structures ◽  
Noble Metals ◽  
High Symmetry ◽  
Face Centered Cubic ◽  
Fcc Metals ◽  
Hexagonal Close Packed ◽  
The Subject ◽  
Hcp Structure ◽  
Face Centered ◽  
High Degree

Noble metals (Ru, Os, Rh, Ir, Pd, Pt, Ag, and Au) are known for their extraordinary oxidant-resistant behavior, good electrical and thermal conductivity, high work function, and brilliant luster. All occur in close-packed crystal structures: Ru and Os in hexagonal close-packed (hcp) and the rest in face-centered cubic (fcc) structures, both possessing high-symmetry structures and, therefore, a high degree of stabilization. Numerous studies in the literature have attempted to stabilize these metals away from their conventional crystal structures with the aim of realizing new properties. While obtaining conventional fcc metals in hcp structure or vice versa has been the subject of most studies, there are also examples of fcc metals crystallizing in lower-symmetry structures such as monoclinic. The nonnative crystal structures are generally realized during the crystallite growth itself, with a few exceptions in which a posttreatment was required for lattice transformation. In most cases, the new crystal structures pertain to the nanometer-length scale in the form of nanoparticles, nanoplates, nanoribbons, and nanowires, but there are good examples from microcrystallites as well. In this article, we review this active area of research, focusing on ambient stable crystal systems with some account of their interesting properties as reported in recent literature.

Epitaxial Growth of Metastable Facf—Centered Cubic Co on (111)Si with A Thin Intermediate Cu Layer

1995 ◽  
Vol 382 ◽  
Author(s):  
C.S. Liu ◽  
L.J. Chen
Keyword(s):  
Epitaxial Growth ◽  
Room Temperature ◽  
Vacuum Chamber ◽  
Metastable Phase ◽  
Ultrahigh Vacuum ◽  
Face Centered Cubic ◽  
Hexagonal Close Packed ◽  
Hcp Structure ◽  
Face Centered ◽  
Interface Compound

ABSTRACTMetastable face—centered cubic (fcc) Co was grown epitaxially on (111)Si with an intermediate Cu layer in an ultrahigh vacuum chamber at room temperature. The metastable fcc—Co was grown to extend to a thickness of 30 nm. Polycrystalline and epitaxial hexagonal close—packed (hcp) Co was grown on (111)Si without and with 3 nm or thicker intermediate Cu layer, respectively. The key to the successful growth of fcc—Co is to deposit Co directly onto a thin (2 nm or thinner) interface compound (—Cu, which is of hcp structure and consisting of 11.2 to 14.0 at.% Si. The growth of the metastable phase is attributed to the attainment of an appropriate electron/atomratio at the interface to favor the formation of the fcc—Co.

Diffraction Stress Analysis of Fiber Textured Ti Thin Films Undergoing hcp - fcc Phase Transformation

2013 ◽  
Vol 768-769 ◽  
pp. 257-263
Author(s):  
Jay Chakraborty
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Stress Analysis ◽  
Group Method ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Hexagonal Close Packed ◽  
Face Centered ◽  
Fcc Phase ◽  
Ti Films

X-ray diffraction stress analysis by crystallite group method (CGM) has been employed in case of simultaneously strong and sharp fiber textured Ti thin films. These Ti films exhibit thickness dependent hcp-fcc phase transformation [Ref. 1]. Diffraction stress analysis has also been attempted by d-sin2 method for strongly textured face centered cubic (fcc) and hexagonal close packed (hcp) Ti phases. For hcp Ti phase, the results of stress analysis by CGM are compared with those obtained from d-sin2 method. It is found that the stress values in hcp Ti phases obtained from CGM considerably differ from the stresses obtained from d-sin2 method in some of the Ti films. Observed differences have been explained and possible sources of errors in d-sin2 method and CGM stress analysis have been discussed.

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