0000000000482380

AUTHOR

Kalevi Kokko

showing 3 related works from this author

Density functional theory description of random Cu-Au alloys

2019

Density functional alloy theory is used to accurately describe the three core effects controlling the thermodynamics of random Cu-Au alloys. These three core effects are exchange correlation (XC), ...

Materials scienceta114tiheysfunktionaaliteoriaAlloyThermodynamics02 engineering and technologyengineering.materialelectronic structure021001 nanoscience & nanotechnology01 natural sciencesCore (optical fiber)Condensed Matter::Materials Sciencealloysfirst-principles calculations0103 physical sciencesengineeringDensity functional theorymetalliseokset010306 general physics0210 nano-technologyta116density functional theoryPhysical Review B
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Space partitioning of exchange-correlation functionals with the projector augmented-wave method

2018

We implement a Becke fuzzy cells type space partitioning scheme for the purposes of exchange-correlation within the GPAW projector augmented-wave method based density functional theory code. Space partitioning is needed in the situation where one needs to treat different parts of a combined system with different exchange-correlation functionals. For example, bulk and surface regions of a system could be treated with functionals that are specifically designed to capture the distinct physics of those regions. Here, we use the space partitioning scheme to implement the quasi-nonuniform exchange-correlation scheme, which is a useful practical approach for calculating metallic alloys on the gene…

Surface (mathematics)Correctnessprojector augmented wave methodFOS: Physical sciencesGeneral Physics and Astronomy010402 general chemistry01 natural sciencesFuzzy logiclaw.inventionSet (abstract data type)alloyslaw0103 physical sciencesmetalliseoksetPhysical and Theoretical ChemistrySpace partitioningta116density functional theoryPhysicsCondensed Matter - Materials Scienceta114010304 chemical physicsgeneralized gradient approximationsPartitions (building)tiheysfunktionaaliteoriaMaterials Science (cond-mat.mtrl-sci)0104 chemical sciencesexchange correlation functionalsProjectorVoronoi diagramsDensity functional theoryProjector augmented wave methodDensity functional theoryapproksimointiAlgorithmThe Journal of Chemical Physics
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Oxidation-Induced Changes in the ALD-Al2O3/InAs(100) Interface and Control of the Changes for Device Processing

2018

InAs crystals are emerging materials for various devices like radio frequency transistors and infrared sensors. Control of oxidation-induced changes is essential for decreasing amounts of the harmful InAs surface (or interface) defects because it is hard to avoid the energetically favored oxidation of InAs surface parts in device processing. We have characterized atomic-layer-deposition (ALD) grown Al2O3/InAs interfaces, preoxidized differently, with synchrotron hard X-ray photoelectron spectroscopy (HAXPES), low-energy electron diffraction, scanning tunneling microscopy, and time-of-flight elastic recoil detection analysis. The chemical environment and core-level shifts are clarified for w…

hapetusMaterials science02 engineering and technologyHigh-electron-mobility transistor01 natural sciences114 Physical scienceslaw.inventionAtomic layer depositionX-ray photoelectron spectroscopyInAslawsynchrotron0103 physical sciencesGeneral Materials Science010302 applied physicsta114business.industryDangling bondatomikerroskasvatus021001 nanoscience & nanotechnologyIII-V semiconductorCrystallographic defectElastic recoil detectionoxidation (active)Electron diffractionatomic layer depositionOptoelectronicsScanning tunneling microscope0210 nano-technologybusinessphotoelectron
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