Structure and properties of YAlO3/NbC heterogeneous nucleation interface: First principles calculation and experimental research

Abstract

Structure and properties of YAlO3/NbC heterogeneous nucleation interface: First principles calculation and experimental research http://researchonline.ljmu.ac.uk/id/eprint/9834/ Article LJMU has developed LJMU Research Online for users to access the research output of the University more effectively. , Q (2018) Structure and properties of YAlO3/NbC heterogeneous nucleation interface: First principles calculation and experimental research. Journal of Alloys and Compounds, 773. pp. AbstractThe characteristics of YAlO3/NbC heterogeneous nucleation interface are strongly associated with the interfacial structure, electronic construction and properties. The lattice mismatch between low index crystal faces of YAlO3 and NbC was calculated by using the Bramfitt twodimensional lattice mismatch theory. The work of adhesion, interfacial energy and electronic structure of the YAlO3(001)/NbC(100) interface structures were calculated by the first principles method. The charge density difference, electron localization function and crystal orbits overlap population were adopted to analyze the charge transfer and bond characteristics. The microstructure of surfacing alloy was observed by transmission electron microscopy (TEM). The results show that, the two-dimensional lattice mismatch of YAlO3(001)-NbC (100) interface is 5.4%, which testifies that YAlO3 can meet the lattice structure condition of being an effective heterogeneous nucleus of NbC. In all interface structures, the work of adhesion of C-O2 model is the largest (Wad=6.558 J/m 2 ) and the interfacial energy of C-Y model is the smallest (=0.54J/m 2 ). It can be confirmed that the C-Y interface structure is the most stable one, whose interfacial energy is the smallest. The chemical bonds between interface atoms of all models are major covalent bonds and few metal bonds. The calculation results indicate that YAlO3(001) slab and NbC(100) slab can form a stable interface structure. The TEM results verify that the rare earth compound in NbC particle is YAlO3. In addition, NbC growth encircling YAlO3 and they are combined tightly. Therefore, YAlO3 can act as the effective heterogeneous nucleus of NbC and refine it.

The Stability and Electronic Structure of Cu(200)/AuCu(200) Interface: An Insight from First-Principle Calculation

“…Table 2 shows the interfacial energy of four different stacking models after total relaxation. In general, the smaller the interfacial energy, the more stable the interfacial structure and the better the wettability [34]. As can be seen from the table, compared with other interfaces, the Long bridge interface has the lowest interface energy of 1.083 J/m 2 .…”

Investigation of NbC/TiC Heterogeneous Nucleation Interface by First-Principles and Experimental Methods

“…Therefore, NbC (111) and TiC (111) with thicknesses larger than thirteen atomic layers were chosen to construct the interfaces in the following calculations. The surface energies of NbC and TiC were calculated using the method of Shi et al [16,31], and the results are shown in Figure 1a,b respectively. It is found that the surface energies of Nbterminated and C-terminated NbC (111) are 1.75-2.88 and 5.70-6.83 J/m 2 , respectively.…”

“…One available and effective method of studying an interface is first-principles calculation based on density functional theory (DFT), which has been extensively employed to investigate the micro-characterization of surfaces and interfaces at the atomic scale [14,15]. For example, a previous report revealed the atomic-scale characteristics of the YAlO 3 /NbC interface by DFT calculation and proved the occurrence of NbC growth encircling YAlO 3 by their experimental method [16]. Additionally, the first-principles calculation was used to investigate the electronic and atomic properties of the Al/NbB 2 interface, and the heterogeneous nucleation mechanism of α-Al grains on NbB 2 particles was determined [17].…”

Interfacial Characterization and High‐Temperature Property of NbB2+NbC Nanoparticles‐Reinforced 2219Al Matrix Composite Synthesized by Melt Spinning

“…NbC ceramic particles possess a high melting point (3490 °C), high hardness (HV 2400), a high elasticity modulus (338.5 GPa), a low coefficient of linear expansion (6.5 × 10 −6 K −1 ), and high chemical and physical stability . The melting point, hardness, elasticity modulus, and coefficient of thermal expansion of NbB 2 are 3050 °C, 2600 kg mm −2 , 445 GPa, and 7.44 × 10 −6 K −1 , respectively.…”