Experimental study and MD simulation of damage formation in GaN under atomic and molecular ion irradiation

Karaseov, P. A.; Karabeshkin, K. V.; Mongo, E.E.; Titov, A.I.; Ullah, Mohammad W.; Kuronen, Antti; Djurabekova, Flyura; Nordlund, K.

doi:10.1016/j.vacuum.2016.01.011

Cited by 10 publications

(10 citation statements)

References 16 publications

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“…2 (a) shows the measured decay of the PL signal spectrally integrated over 360 nm peak (see Refs. 30,31) for GaN targets irradiated by monatomic and molecular ions to the dose of 0.8×10 -3 DPA. For clarity in the figure, only one of every five experimental points is shown by markers.…”

Section: Resultsmentioning

confidence: 99%

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Single and molecular ion irradiation-induced effects in GaN: experiment and cumulative MD simulations

Karaseov

Karabeshkin

Titov

et al. 2017

J. Phys. D: Appl. Phys.

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An investigation of mechanisms of enhancement of irradiation-induced damage formation in GaN under molecular in comparison to monatomic ion bombardment is presented. Ionimplantation-induced effects in wurtzite GaN bombarded with 0.6 keV/amu F, P, PF2, and PF4 ions at room temperature are studied experimentally and by cumulative MD simulation in the correct irradiation conditions. In the low dose regime, damage formation is correlated with a reduction in photoluminescence decay time, whereas in the high dose regime, it is associated with the thickness of the amorphous layer formed at the sample surface. In all the cases studied, a switch to molecular ion irradiation from bombardment by its monatomic constituents enhances the damage accumulation rate. Implantation of heavy Ag ion, having approximately the same mass as the PF4 molecule, is less effective in surface damage formation, but leads to noticeably higher damage accumulation in the bulk.. The cumulative MD simulations do not reveal any significant difference in the total amount of both point defects and small defect clusters produced by light monatomic and molecular ions. On the other hand, increased production of large defect clusters by molecular PF4 ions is clearly seen in the vicinity of the surface. Ag ions produce almost the same number of small, but more large defect clusters compare to the others. This findings show that the enhancement of stable damage formation in GaN under molecular, as well as under heavy monatomic ion irradiation, can be related to the higher formation probabilityof large defect clusters.

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Section: Resultsmentioning

confidence: 99%

“…Accordingly, another object of the current study is to obtain experimental confirmation of this prediction. A brief report on preliminary results of experimental and theoretical studies of enhancement of surface disordered layer (SDL) formation was published earlier in [31].…”

Section: Introductionmentioning

confidence: 99%

Single and molecular ion irradiation-induced effects in GaN: experiment and cumulative MD simulations

Karaseov

Karabeshkin

Titov

et al. 2017

J. Phys. D: Appl. Phys.

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“…Thus, the high activation elements (such as Nb) are not preferable for nuclear fission/fusion reactor applications [25,26]. For low-activation TiVZrHfTa and TiVZrTa HEAs, the irradiation-induced hardening effects were suppressed compared to the conventional SS304 alloy and pure V. In recent years, computational simulations become an increasingly important tool to study radiation damage in various metals and alloys [4,23,[27][28][29][30][31][32][33][34]. In this work, molecular statics (MS) calculations and molecular dynamics (MD) simulations were performed to study the defect properties of TiVZrTa HEA.…”

Section: Introductionmentioning

confidence: 99%

Defect properties of a body-centered cubic equiatomic TiVZrTa high-entropy alloy from atomistic simulations

Li¹,

Qiang²

2023

J. Phys.: Condens. Matter

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TiVZrTa high-entropy alloys (HEAs) have been experimentally proven to exhibit excellent irradiation tolerance. In this work, defect energies and evolution were studied to reveal the underlying mechanisms of the excellent irradiation tolerance in TiVZrTa HEA via molecular statics calculations and molecular dynamics simulations. The atomic size mismatch of TiVZrTa is ∼6%, suggesting a larger lattice distortion compared to most face-centered cubic and body-centered cubic M/HEAs. Compared to pure Ta and V, smaller vacancy formation and migration energies with large energy spreads lead to higher equilibrium vacancy concentration and faster vacancy diffusion via low-energy migration paths. Vacancies in TiVZrTa have weaker abilities to form large vacancy clusters and prefer to form small clusters, indicating excellent resistance to radiation swelling. The formation energies of different types of dumbbells in TiVZrTa show significant differences and have large energy spreads. The binding abilities of interstitials in TiVZrTa are weaker compared to that in pure Ta and V. In TiVZrTa, fast vacancy diffusion and slow interstitial diffusion result in closer mobilities of vacancies and interstitials, significantly promoting point defect recombination. We further studied the effects of short-range ordered structures (SROs) on defect diffusion and evolution. SROs in TiVZrTa can effectively lead to higher fractions of defect recombination and fewer surviving defects. Our findings provide a comprehensive understanding of the underlying mechanisms of the high irradiation tolerance in body-centered cubic HEAs with large lattice distortion and suggest SROs are beneficial microstructures for enhancing irradiation tolerance.

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“…Ионы, тормозящиеся в мишени, сталкиваются с атомами в решетке, что приводит к " выбиванию" их из регулярных положений, и образуются так называемые каскады смещений (или каскады столкновений, collision cascade), состоящие из вакансий и межузельных атомов. Экспериментально показано, что плотность каскадов смещений существенным образом влияет на результирующие радиационные повреждения в Si [9][10][11], SiC [12], ZnO [13], GaN [14,15], металлах [16], полимерах [17] и т. д. В частности, было обнаружено усиление образования дефектов в β-Ga 2 O 3 [18]. Также известно, что эффекты, связанные с плотностью каскадов, удобно изучать, проводя сравнение накопления повреждений при облучении атомарными и молекулярными ионами [9,[12][13][14]17,19].…”

Section: Introductionunclassified

Накопление структурных нарушений при облучении α-Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- ионами P и PF-=SUB=-4-=/SUB=-

Карасев¹,

Карабешкин²,

Стручков³

et al. 2022

Физика И Техника Полупроводников

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We study radiation damage accumulation in alphapolymorph of gallium oxide (α-Ga2O3) epitaxial layers under irradiation with 40 keV monatomic P and 140 keV molecular PF4 ions. The distribution of stable structural damage is bimodal in both cases. The growth rate of the surface disordered layer under PF4 ion irradiation is significantly higher than that under monatomic P ion bombardment. At the same time, monatomic ion irradiation is more efficient in the bulk defect peak formation. Thus, the density of displacement cascades strongly affects the formation of stable damage in α-gallium oxide. The doses required to create the same level of disorder in the metastable α-polymorph are higher than that in the thermodynamically stable β-Ga2O3. Mechanisms of damage formation in these polymorphs are different.

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Experimental study and MD simulation of damage formation in GaN under atomic and molecular ion irradiation

Cited by 10 publications

References 16 publications

Single and molecular ion irradiation-induced effects in GaN: experiment and cumulative MD simulations

Single and molecular ion irradiation-induced effects in GaN: experiment and cumulative MD simulations

Defect properties of a body-centered cubic equiatomic TiVZrTa high-entropy alloy from atomistic simulations

Накопление структурных нарушений при облучении α-Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- ионами P и PF-=SUB=-4-=/SUB=-

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Experimental study and MD simulation of damage formation in GaN under atomic and molecular ion irradiation

Cited by 10 publications

References 16 publications

Single and molecular ion irradiation-induced effects in GaN: experiment and cumulative MD simulations

Single and molecular ion irradiation-induced effects in GaN: experiment and cumulative MD simulations

Defect properties of a body-centered cubic equiatomic TiVZrTa high-entropy alloy from atomistic simulations

Накопление структурных нарушений при облучении &alpha;-Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- ионами P и PF-=SUB=-4-=/SUB=-

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Накопление структурных нарушений при облучении α-Ga-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- ионами P и PF-=SUB=-4-=/SUB=-