Applicability of a linear diffusion model to determination of the height of the potential barrier at the grain boundaries of Fe-doped SrTiO3

2018 ◽  
Vol 20 (28) ◽  
pp. 19250-19256 ◽  
Author(s):  
Chih-Yuan S. Chang ◽  
Igor Lubomirsky ◽  
Sangtae Kim
Keyword(s):  
Grain Boundaries ◽  
Diffusion Model ◽  
Potential Barrier ◽  
Experimental Verification ◽  
Electron Hole ◽  
Linear Diffusion

Experimental verification of a linear diffusion model on a lightly doped electron–hole conductor, Fe-doped SrTiO3.

The exceptionally large height of the potential barrier at the grain boundary of a LaGaO3-based solid solution deduced from a linear diffusion model

2018 ◽  
Vol 20 (13) ◽  
pp. 8719-8723 ◽  
Author(s):  
Chih-Yuan S. Chang ◽  
Igor Lubomirsky ◽  
Sangtae Kim
Keyword(s):  
Solid Solution ◽  
Grain Boundary ◽  
Diffusion Model ◽  
Potential Barrier ◽  
Experimental Verification ◽  
Resistivity Ratio ◽  
Linear Diffusion ◽  
Boundary Potential

Experimental verification of consistency in the grain boundary potential heights deduced from the linear diffusion and the resistivity ratio methods.

On determining the height of the potential barrier at grain boundaries in ion-conducting oxides

2016 ◽  
Vol 18 (4) ◽  
pp. 3023-3031 ◽  
Author(s):  
Sangtae Kim ◽  
Seong K. Kim ◽  
Sergey Khodorov ◽  
Joachim Maier ◽  
Igor Lubomirsky
Keyword(s):  
Grain Boundary ◽  
Space Charge ◽  
Grain Boundaries ◽  
Potential Barrier ◽  
Boundary Resistance ◽  
Resistivity Ratio ◽  
Linear Diffusion ◽  
Conducting Oxides ◽  
Ion Conducting

Combining the linear diffusion and resistivity ratio models, one can distinguish the grain boundary resistance related to space charge from the resistance from other sources.

A linear diffusion model for ion current across blocking grain boundaries in oxygen-ion and proton conductors

2014 ◽  
Vol 16 (28) ◽  
pp. 14961-14968 ◽  
Author(s):  
Seong K. Kim ◽  
Sergey Khodorov ◽  
Igor Lubomirsky ◽  
Sangtae Kim
Keyword(s):  
Grain Boundaries ◽  
Diffusion Model ◽  
Solid Electrolytes ◽  
Proton Conductors ◽  
Ion Current ◽  
Linear Diffusion ◽  
Oxygen Ion ◽  
Current Voltage ◽  
Current Voltage Characteristics

We demonstrate the applicability of the linear diffusion model recently proposed for the current–voltage characteristics of grain boundaries in solid electrolytes.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

scholarly journals Effects of Charge Compensation on Colossal Permittivity and Electrical Properties of Grain Boundary of CaCu3Ti4O12 Ceramics Substituted by Al3+ and Ta5+/Nb5+

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3294
Author(s):  
Jakkree Boonlakhorn ◽  
Jedsada Manyam ◽  
Pornjuk Srepusharawoot ◽  
Sriprajak Krongsuk ◽  
Prasit Thongbai
Keyword(s):  
Dielectric Properties ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Barrier Height ◽  
Potential Barrier ◽  
Charge Compensation ◽  
Solid State Reaction Method ◽  
Wide Frequency Range ◽  
Potential Barrier Height

The effects of charge compensation on dielectric and electrical properties of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics (x = 0−0.05) prepared by a solid-state reaction method were studied based on the configuration of defect dipoles. A single phase of CaCu3Ti4O12 was observed in all ceramics with a slight change in lattice parameters. The mean grain size of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics was slightly smaller than that of the undoped ceramic. The dielectric loss tangent can be reduced by a factor of 13 (tanδ ~0.017), while the dielectric permittivity was higher than 104 over a wide frequency range. Impedance spectroscopy showed that the significant decrease in tanδ was attributed to the highly increased resistance of the grain boundary by two orders of magnitude. The DFT calculation showed that the preferential sites of Al and Nb/Ta were closed together in the Ti sites, forming self-charge compensation, and resulting in the enhanced potential barrier height at the grain boundary. Therefore, the improved dielectric properties of CaCu3Ti4-x(Al1/2Ta1/4Nb1/4)xO12 ceramics associated with the enhanced electrical properties of grain boundaries. In addition, the non-Ohmic properties were also improved. Characterization of the grain boundaries under a DC bias showed the reduction of potential barrier height at the grain boundary. The overall results indicated that the origin of the colossal dielectric properties was caused by the internal barrier layer capacitor structure, in which the Schottky barriers at the grain boundaries were formed.

Multi-spacecraft collaborative attitude determination of space tumbling target with experimental verification

2021 ◽  
Vol 185 ◽  
pp. 1-13
Author(s):  
Di Zhao ◽  
Chong Sun ◽  
Zhanxia Zhu ◽  
Wenya Wan ◽  
Zixuan Zheng ◽  
...  
Keyword(s):  
Experimental Verification ◽  
Attitude Determination ◽  
Tumbling Target

scholarly journals Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases

2018 ◽  
Vol 64 (246) ◽  
pp. 669-674
Author(s):  
COLIN M. SAYERS
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Orientation Distribution ◽  
Resonant Ultrasound Spectroscopy ◽  
Wave Velocities ◽  
Polycrystalline Ice ◽  
Resonant Ultrasound ◽  
Increasing Temperature ◽  
Shear Compliance

ABSTRACTMeasured elastic stiffnesses of ice polycrystals decrease with increasing temperature due to a decrease in grain boundary stiffness with increasing temperature. In this paper, we represent grain boundaries as imperfectly bonded interfaces, across which traction is continuous, but displacement may be discontinuous. We express the additional compliance due to grain boundaries in terms of a second-rank and a fourth-rank tensor, which quantify the effect on elastic wave velocities of the orientation distribution as well as the normal and shear compliances of the grain boundaries. Measurement of the elastic stiffnesses allows determination of the components of these tensors. Application of the method to resonant ultrasound spectroscopy measurements made on ice polycrystals enables determination of the ratio BN/BS of the normal to shear compliance of the grain boundaries, which are found to be more compliant in shear than in compression. The ratio BN/BS is small at low temperatures, but increases as temperature increases, implying that the normal compliance increases relative to the shear compliance as temperature increases.

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