Trushin Yu. V., Kulikov D. V., Kharlamov V. S.
High-dose radiation processes in multiatomic and multicomponent materials: theory and computer modelling.
(in russian)
Izv. RAN, ser. phys, v. 62, N 7, 1998, pp. 1421-1424

Yu.V.Trushin, D.V. Kulikov
Theory and computer simulation of radiation defects in crystals
Proc.of the 4th Moscow Int. ITEP School of Physics, Zvenogorod, Moscow, Feb.5-16, pp.84-112, 2001

The methods and approaches of theoretical investigations of radiation processes in solids are presented. This includes primary effects of atoms displacements (ballistic processes), diffusion processes, evolution of microstructure during and after irradiation and resulting changes in material properties. Several examples of using the theory and simulation for investigation of radiation processes are presented.

Abstracts of Nanotechnologies in the area of physics, chemestry and biology, Fifth ISTC Scientific Advisory Committee Seminar, St Petersburg, Russia, 2002, p. 101
Combined experimental and computer simulation technique for the restoration of in-depth elemental distributions in SIMS profiling analysis of nanostructures
Yu.V. Trushin, B.Ja. Ber, E.E. Zhurkin, D.V. Kulikov, V.S. Kharlamov and A.A. Schmidt

Tech. Phys. Lett., vol. 23(8), 1997, pp. 617-620
High-temperature high-dose implantation of N⁺ and Al⁺ ions in 6H-SiC
R. A. Yankov, M. Voelskow, W. Kreissig, D. V. Kulikov, J. Pezoldt, W. Skorupa, Yu. V. Trushin, V. S. Kharlamov, D. N. Tsigankov

A series of experimental and theoretical investigations has been initiated for 6H-SiC samples sequentially implanted with high doses of N⁺ (65 keV) + N⁺ (120keV) + Al⁺ (100keV) + Al⁺ (160 keV) ions at temperatures between 200 and 800^oC. Nytrogen and carbon distribution profiles are measured by ERD and structural defect disributions are measured by Rutherford backscattering with channeling. A comparison between the experimental data and the results of computer simulation yields a physical model to describe the relaxation processes opf the implanted SiC structure, where the entire implanted volume is devided into regions of different deph, having different guiding kinetics mechanisms.  

Proc. of SPIE, vol. 3345, 1998, pp. 260-263
Computer simulation RBS/C studies of high dose N⁺ and Al⁺ co-implantation in 6H-SiC
V. S. Kharlamov, D. V. Kulikov, Yu. V. Trushin, D. N. Tsigankov, R. A. Yankov, M. Voelskow, W. Skorupa, J. Pezoldt

The (SiC) (AlN) system is being extensively investigated due to the full miscibility of the two constituents, SiC and AlN, their good thermal and lattice matches, and the the possibility of modifying the band gap of the resulting structure over a wide range of 2.9 eV (6H-SiC) to 6.2 eV (2H-AlN). From a practical viewpoint, the solid solutions of SiC and AlN are promising materials for advanced high-temperature electronic and optoelectronic devices. One novel method of producing thin layers of (SiC)(AlN) potentially suitable for microelectronic applications is the use of N and Al co-implantation into 6H-SiC at elevated temperatures followed by annealing, i. e. ion-beam synthesis. Hitherto, to the best of our knowledge, there has been only one report on the formation of buried (SiC)(AlN) layers in 6H-SiC by ion-beam synthesis. This work is an attempt to model the fundamental processes that occur when 6H-SiC is implanted at elevated substrate temperatures with high doses of N⁺ and Al⁺ ions to form thin buried layers of (SiC)(AlN) having predetermined composition and dimensions. Results from the calculations have been correlated with those obtained by Rutherford backscattering channelling spectrometry (RBS/C).  

Materials Science Forum, vol. 264-268, 1998, pp. 757-760
A computational model of the formation of (SiC)(AlN) by hot, high-dose N⁺ and Al⁺ co-implants in 6H-SiC
Yu. V. Trushin, R. A. Yankov, V. S. Kharlamov, D. V. Kulikov, D. N. Tsigankov, U. Kreissig, M. Voelskow, J. Pezoldt, W. Skorupa

This work is an attempt to model the processes that occur when 6H-SiC is implanted at elevated substrate temperatures with high doses of N⁺ and Al⁺ ions to form thin buried layers of (SiC)(AlN). The theoretical treatment has involved ballistic calculations of the distribution of the above species and the resulting ion-induced defects by means of computer codes (developed specially for modelling multi-elemental targets) that take into account the effect of cascade overlapping at high ion doses. Results from the computer simulations have been correlated with data obtained by Rutherford backscattering spectrometry/ion channeling (RBS/C) and elastic recoil detection (ERD) techniques, and good agreement has been achieved between theory and experiment. The analysys of the theoretical and experimental findings has enabled five specific regions to be identified in the implanted material which are discus-sed in detail.  

Tech. Phys. Lett., vol. 24(1), 1998, pp. 17-19
Theoretical description of Al⁺ and N⁺ high-temperature co-implantation in silicon carbide
D. V. Kulikov, Yu. V. Trushin, R. A. Yankov, J. Petzold, W. Skorupa

A theoretical analysis of the evolution of the defect structure in silicon carbide (6H-SiC) implanted with N⁺ and Al⁺ ions of various energies. Satisfactory agreement was achieved between the calculated defect distributions and experimental data. The following kinetic parameters of silicon carbide were estimated numerically: the migration energy of interstitial silicon atoms and the recombination parameters of vacancies and interstitial sites in the carbon and silicon subsystems.

Proceedings ot the 1st Moscow International ITEP School of Physics, Zvenigorod, Feb. 17-26, 1998, p. 249-251
Modeling of defect distributions in silicon carbide irradiated by N⁺ and Al⁺ ions with internal stress field taken into consideration
(in russian)
P.V. Rybin, D.V. Kulikov, Yu.V. Trushin

Tech. Phys., vol. 44(10), 1999, pp. 1168-1174
Physical model for the evolution of the defect system of silicon carbide with allowance for the internal elastic stress fields during implantation of Al⁺ and N⁺ and subsequent annealing
D. V. Kulikov, Yu. V. Trushin, P. V. Rybin, V. S. Kharlamov

A theoretical analysis is offered for the formation and development of defects in silicon carbide implanted with nitrogen and aluminum ions and annealed. The diffusion of defects, the formation of complexes, and the influence of the internal elastic stress fields produced by the implanted ions and the created complexes on the migration of interstitials are taken into account. The computed distributions of defects agree satisfactory with the experimental data. acertain kinetic parameters of silicon carbide are estimated numerically.  

Nucl. Instr. and Meth. B 147, 1999, pp. 279-285
Modelling high-temperature co-implantation of N⁺ and Al⁺ ions in silicon carbide: the effect of stress on the implant and damage distributions
P.V. Rybin, D.V. Kulikov, Yu.V. Trushin, R.A. Yankov, G. Ecke, W. Fukarek, W. Skorupa, J. Pezoldt

This work is an initial attempt to model the fundamental processes that occur when SiC is implanted at elevated substrate temperatures T_i (200^o-800^o) with high doses of N⁺ and Al⁺ ions to synthesise buried layers of (SiC)_1-x (AlN)_x. The theoretical treatment has involved ballistic calculation of the implant and damage profiles by means of computer codes (TRIRS and DYTRIRS) specifically developed for modelling complex, multi-elemental targets. The influence of the mechanical stress induced the by implanted ions has been taken into account by adding a special term to the differential equations describing the evolution of the implant and damage distributions. Results from the simulations have been correlated with data obtained by Rutherford backscattering spectrometry/ion channelling (RBS/C). The theoretical approach described has enabled one to determine the interaction energies of the interstitials with the internal stress field as well as the role of stress on the defect distribution.

Proc. of SPIE, vol. 3687, 1999, pp. 254-257
Theoretical and experimental studies of (AlN)_1-x (SiC)_x layer structures formed by N⁺ and Al⁺ co-implantation in 6H-SiC
D.V. Kulikov, J. Pezoldt, P.V. Rybin, W. Skorupa, Yu.V. Trushin, R.A. Yankov

In present work the defect formation and in silicon carbide implanted with N⁺ and Al⁺ ions and annealled has been investigated experimentally and theoretically. The model of defect evolution in implanted and annealed silicon carbide has been developed taking into account the influence of internal stress field on interstitials diffusion. The satisfactory agreement of theoretical and experimental results has been obtained. The parameter of interaction of interstitials with stress field has been estimated.

Proc. of SPIE, vol. 4064, 2000, pp. 301-307
Influence of internal strees field due to point defect clusters on interstitial diffusion in SiC under irradiation
P.V. Rybin, D.V. Kulikov, Yu.V. Trushin, J. Petzoldt, R.A. Yankov

The fundamental processes that occur when SiC is implanted at elevated substrate temperatures with high doses of N⁺ and Al⁺ ions to synthesise buried layers of (SiC)_x (AlN)_1-x have been investigated. The influence of the mechanical stress induced by formed clusters of interstitials has been taken into account by adding special term to the expression of current density of defects in the set of differential equations. The satisfactory agreement of simulation results and experimental data is obtained. The theoretical treatment has enabled one to determine the role of internal stress field on the evolution of defect distribution.

Nucl. Instr. & Meth. in Phys. Res. B, vol. 166/167 (1-4), 2000, pp. 758-763
The influence of the implantation sequence on the (SiC)_1-x (AlN)_x formation
J. Pezoldt, P.V. Rybin, D.V. Kulikov, Yu.V. Trushin, R.A. Yankov, M. Voelskow, U. Kreissig

The influence of the implantation sequence on the defect and implant distribution during (SiC)_1-x (AlN)_x formation was studied by Rutherford backscattering spectrometry/ion channelling (RBS/C) and elastic recoil detection. It is shown that the implantation sequence aluminum followed by nitrogen lead to an improved crystallinity compared to the reverse implantation sequence for implantation temperatures above 400^o C. The results obtained are discussed in relation to the defects distributions calculated by using a developed model which includes the effect of stress self-consistently.

Proc. of SPIE, vol. 4348, 2001 pp. 257-263
Al⁺ and N⁺ implantation in silicon carbide: a role of point defect clusters in defect evolution.
P.V.Rybin, D.V.Kulikov, Yu.V.Trushin, J. Petzoldt

The diffusion processes in silicon carbide under Al⁺ and N⁺ ion implantation and subsequent annealing have been investigated. The influence of an internal stress field due to point defect clusters has been taken into account. The clusters of interstitials, ions and impurities have been created during irradiation. The compression stress field due to these complexes has decreased the diffusion of interstitials. The defect profiles have been calculated which have been in good agreement with experimental RBS/C results.

Phys. Solid State, vol. 36(10), 1994, pp. 1583-1589
Physical model of the oxygen subsystem in YBaCuO during gamma-irradiation
D. V. Kulikov, R. A. Suris, Yu. V. Trushin

A theoretical investigation is made of the influence of processes taking place in the oxygen subsystem of thin YBaCuO films under the influence of gamma irradiation on the value of crytical temperature of superconducting transition and the dependence of the resistivity on the temperature. Estimates of the numerical values are obtained for the following parameters of oxygen subsystem of thin YBaCuO films: the sink strength, the energy of binding of the oxygen to a sink, and the cross section for the formation of an oxygen vacancy by ionization during gamma irradiation.  

Supercond. Sci. Technol., vol. 8, 1995, pp. 303-310
A model of oxygen-subsystem defects interaction with intercrystalline boundaries in polycrystalline YBaCuO films under gamma-irradiation
D. V. Kulikov, R. A. Suris, Yu. V. Trushin

The influence of processes occuring in the oxygen subsystem of YBaCuO thin films under gamma-irradiation on the critical temperature and on the temperature dependence of the film resistance has been investigated theoretically. The values of parameters such as sink strength values, the energy barrier for oxygen escape from sinks and cross-section of oxygen-vacancy formation under gamma-irradiation have been estimated.  

Tech. Phys. Lett., vol. 22(11), 1996, pp. 920-922
Computersimulation of point magnetic-flux pinningcenters in a neutron-irradiated YBaCuO single crystal
D. V. Kulikov, R. A. Suris, Yu. V. Trushin, V. S. Kharlamov,D. N. Tsigankov

A model is presented for the evolution of point defects generated by neutron irradiation in YBaCuO. The concentrations of point defects generated by the neutron irradiaion are calculated. It is shown that by annealing the irradiated sample at room temperature (in the reactor channel) it is possible to form small clusters of point defects in concentrations sufficient for effective pinning of the magnetic flux. This model can explain the anisotropy in the lowering of the critical current density by annealing of irradiated samles and shows that the critical current in the presence of a magnetic field parallel to ab-plane is proportional to the concentration of pinning defects.  

Physica C, vol. 282/287, 1997, pp. 1333-1334
Small defects in YBCO single crystals: Tc after neutron irradiation and annealing
F. M. Sauerzopf, M. Werner, H. W. Weber, R. A. Suris, D. V. Kulikov, V. S. Kharlamov, Yu. V. Trushin

Neutron irradiation of HTCs creates a wide spectrum of defect sizes. In this work, the influence of small defects on the critical temperature is investigated by sequential reactor neutron irradiation and annealing of a YBCO single crystal. Thecharacteristic behaviour of Tc under this treatment is satisfactorily explained by a theoretical model considering the creation, migration and annihilation of small defects in the oxygen sublattice.  

Proc. of SPIE, vol. 3345, 1998, pp. 241-248
Physical model of pinning centers annealing processes in neutron irradiated YBaCuO
Kulikov D. V., Suris R. A., Trushin Yu. V., Kharlamov V. S., Tsigankov D. N.

Neutron irradiation of HTSCs creates a wide spectrum of defect sizes. In this work, the influence of small defects on the critical temperature and critical current density Jc is investigated. The characteristic behaviour of Tc and Jc under this treatment is satisfactorily explained by a theoretical model considering the creation, migration and annihilation of small defects in the oxygen sublattice.  

Physica C, v.355 (2001) p.245-250
Changes in the transition temperature after irradiation and annealing in single crystalline YBaCuO
D.V. Kulikov, Yu.V. Trushin, F.M. Sauerzopf, M. Zehetmayer, H.W. Weber

We present a model of the defect dynamics in YBaCuO crystals to understand the changes in the transition temperature after neutron irradiation and subsequent annealing. These changes are closely related to the calculated concentration of vacancies in the Cu-O chain sites.

Tech. Phys. Lett., v. 27(4), 2001, pp. 316-318
A physical model of oxygen subsystem evolution in PLZT-ceramics under neutron irradiation and annealing
D.V. Kulikov, D.A. Lesnyh, Yu.V. Trushin, H.W.Weber, K.Humer, R.Bittner, A.R.Sternberg

A physical model describing the evolution of defects in the oxygen subsystem of ferroelectric PLZT ceramics under neutron irradiation and isochronous annealing conditions is proposed. The model takes into account the dependence of the material properties on the lanthanum content. The oxygen vacancy concentration variations calculated using this model agree with the experimental data on the polarization behavior in annealing ceramics.

Proc.of SPIE v.4348, 2001, pp.264-269
Computer simulation of ferroelectric property changes in PLZT ceramics under neutron irradiation.
D.V. Kulikov, Yu.V. Trushin, V.S. Kharlamov, R.Bittner, K.Humer, H.W. Weber, A.R. Sternberg, D.A. Lesnyh, A.A. Schmidt

The response of ferroelectric materials to high energy irradiation is of great interest because of their possible application in radiation environments such as thermonuclear reactors. In the present work a physical model for the defect evolution in PLZT ceramics under neutron irradiation and annealing is proposed. The influence of the defect system on the ferroelectric properties of these materials has been investigated. Satisfactory agreement between the theoretically estimated oxygen defect concentration after irradiation and annealing and the experimentally determined polarization has been obtained.

Integrated Ferroelectrics v.37, 2001, p.275
Dielectric properties of reactor irradiated ferroelectric thin films.
R. Bittner, K. Humer, H.W. Weber, M. Tyunina, L. Cakare, A. Sternberg, D.V. Kulikov, Y.V. Trushin

Proc. of SPIE, v.4627, 2002, pp.170-176
Computational study of the influence of oxygen vacancies on the polarization in irradiated and annealed PLZT ceramics
D. A. Lesnyh, D. V. Kulikov, Yu.V. Trushin, R. Bittner, K. Humer, H.W. Weber, A.R. Sternberg

A physical model for the oxygen defect evolution in PLZT ceramics under neutron irradiation and annealing is proposed. The influence of the defect system on the polarization of these materials has been investigated. The influence of the La content on the material structure and the oxygen defects has been taken into account. Satisfactory agreement between the theoretically estimated oxygen defect concentration after irradiation and annealing and the experimentally determined polarization has been obtained.

Tech. Phys. Lett., v.28, No.8, 2002, pp. 628-630
The effect of neutron irradiation on the Curie-Weiss temperature of an antiferroelectric lead-zirconate film
D.V Kulikov, D.A.Lesnyh, Yu.V. Trushin, H.W. Weber, K.Humer, R.Bittner, A.R.Sternberg

Integrated Ferroelectrics v.47, 2002, p.143
Dielectric properties of irradiated ferroelectric and antiferroelectric thin films
R. Bittner, K. Humer, H.W. Weber, L. Cakare, A. Sternberg, D.V. Kulikov, Y.V. Trushin

Proc. of SPIE, N5122, 2003, pp.341-347
Irradiation effects in lead zirconate thin films
A.R. Sternberg, A. Krumins, K. Kundzins, V. Zauls, I. Aulika, L. Cakare, R. Bittner, H. Weber, K. Humer, D. Lesnyh, D. Kulikov, Y. Trushin

Proc. of SPIE, v.5127, 2003, pp.136-139
Chnages in the temperature dependence of the dielectric constant in irradiated antiferroelectric thin films
D.A. Lesnyh, D.V. Kulikov, Yu.V. Trushin, R. Bittner, K. Humer, H. Weber, A. Sternberg

A model describing the changes of the Curie-Wiss temperature in lead-zirconate thin films under neutron irradiation is proposed. The Curie-Weiss temperature in the irradiated material decreases proportionally to the square of the neutron fluence. This decrease is connected to charges caused by neutron irradiation, which are equally distributed over the film. Satisfactory agreement between theoretical results and experimental data is obtained for different neutron fluences.

Journal of the European Ceramic Society, v.24, Issue 6, pp. 1653-1657, 2004
Antiferroelectric PbZrO3 thin films: structure, properties and irradiation effects
A. Sternberg, K. Kundzins, V. Zauls, I. Aulika, L. Cakare, R. Bittner, H. Weber, K. Humer, D. Lesnyh, D. Kulikov, Y. Trushin

Proc. of the 4th Moscow Int. ITEP School of Physics, Zvenigorod, Moscow, Feb.5-16, pp.299-303, 2001
Growth of SiC nanoclusters on Si surface using Molecular beam epitaxy
D.V. Kulikov, K.L. Safonov, Yu.V. Trushin, J. Pezoldt

The growth of SiC clusters on a Si(111) surface has been investigated theoretically. The formation and growth of SiC clusters on a Si surface stimulated by the deposition of elemental carbon onto Si(111) using molecular beam expitaxy, have been studied by applying the kinetic equation method. The simulated cluster size distribution function obtained within this method appeared to be in reasonable agreement with experimental data.

Proc. of SPIE, v.4627, 2002, pp.165-169
Nucleation of SiC on Si and their relationship to nano-dot formation: II. Theoretical investigation
K.L. Safonov, D.V. Kulikov Yu.V. Trushin, Joerg Pezoldt

The processes of SiC clusters growth on Si(111) surface has been investigated theoretically. The SiC cluster formation and growth on Si surface stimulated by deposition of elemental carbon onto Si(111) with molecular beams have been studied by applying the kinetic equations (co-called rate equations) method. The simulated cluster size distribution function obtained within this method appeared to be in reasonable agreement with the experimental data. Obtained cluster capture rates agree with KMC investigations.

Proc. of SPIE, v.5127, 2003, pp.128-131
Influence of the growth temperature on SiC nanocluster nucleation on Si(111) surface during MBE process
K.L. Safonov, D.V. Kulikov, Yu.V. Trushin, J. Pezoldt

Rate equations approach of computer simulation has been applied to investigate the SiC clusters nucleation and growth on Si surface during molecular beam epitaxy. Cluster surface densities have been obtained for a range of temperatures. The temperature influence on the cluster density, including the surface phase transition (which occurs with simultaneous surface structure reconstruction), has been determined. The results obtained bythe application of the suggested physical model have appeared to be in the reasonable agreement with experimental data.

Mater. Sci. Forum, v.433-436, 2003, pp.591-594
Modelling the formation of nano-sized SiC on Si
K.L. Safonov, A.A. Schmidt, Yu.V. Trushin, D.V. Kulikov, J. Pezoldt

Tech. Phys. Lett., v.23(7), 1997, pp. 573-574
Physical model of the formationof a periodic structure on the surface of pyrolitic graphite under high-energy ion bombardment
D. V. Kulikov, R. A. Suris, A. L. Suvorov, Yu. V. Trushin, V. S. Kharlamov

A physical model is presented for the formation of a structure consisting of "micropoints" and "cavities" on the surface of pyrolitic graphite bombarded by 210 MeV Kr⁺ ions. This structure may be explained in terms of the depth distribution of the energy deposited by the bombardment.  

Vacuum, vol. 52, 1999, pp. 407-410
Computer simulation of transition from h-BN to c-BN during ion beam assisted deposition
V. S. Kharlamov, D. V. Kulikov, Yu. V. Trushin

A model is proposed of c-BN growth during the ion Beam assisted deposition procces. This phase appears when N and B atoms in h-BN create inserted ab-planes that increase the density of the material, resulting in transition from h-BN to c-BN. The aim is to simulate the processes that occur in growing BN films that lead to the phase transition. The ballistic processes caused by ion beam have been simulated by means of Monte Carlo computer codes TRIRS and DYTRIRS. With the help of computer code GEAR the annealing of the profiles of bombarding particles (Ar, N, B) have been modelled. The sink strengths of dislocation loops and migration energies of Ar, B and N atoms in BN have been estimated. These loops can act as nuclei of inserted ab-planes consisted of B and N, leading to formation of c-BN. It is shown that, according to our model, the transition from h-BN to c-BN is indeed possible, under certain conditions.  

Proc. of SPIE, vol. 3687, 1999, pp. 290-291
Physical model of copper clusters formation in hydrogenated amorphous carbon grown by ion co-sputtering of graphite and copper
D.V. Kulikov, Yu.V. Trushin, V.S. Kharlamov

The size distribution function of copper clusters formed in growing DLC films has been obtained by computer simulation. The reasonable agreement of theoretical and experimental results has been achieved. The value of surface activation migration energy of copper has been estimated.

Techn. Phys. Lett., vol. 25(3), 1999, pp. 198-199.
Size distribution of copper nanoclusters in amorphous carbon.
Kulikov D.V., Trushin Yu.V., Kharlamov V.S., Ivanov-Omski V.I.

A theoretical analysis is made of the formation of copper nanoclusters in a growing amorphous carbon film. The calculated size distributions of the copper clusters are compared with the experimental data. A numerical estimate is made of various kinetic parameters of copper in amorphous carbon

Proc of SPIE, vol. 4064, 2000, pp. 288-294
Copper cluster formation and evolution in amorphous materials grown by co-sputtering of copper with SiO₂
Dmitry V. Kulikov, Yurii V. Trushin, Sergey A. Gurevich, Vasiliy A. Zabelin

The process of copper nanoclusters evolution in amorphous films, formed by co-sputtering of Cu and SiO₂, has been investigated theoretically. Bulk copper diffusion during sample annealing after fabrication have been described by kinetic equation set and cluster size distribution function have been obtained. The reasonable agreement of theoretical and experimental results has been achieved. The values of bulk copper activation migration energy have been estimated. For investigating clusters formation with different copper content method of molecular dynamics have been developed. Both methods have reasonable agreement for low time diffusion.