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Andriy Kovalskiy

Professor

Physics, Engineering and Astronomy

 

Ph.D. in Solid State Physics - Ivan Franko National University of Lviv, Ukraine

B.Sc. and M.Sc. Degree in Radioelectronic Materials Engineering - Ivan Franko National University of Lviv, Ukraine

Joined the Department in 2011. Recipient of 2013 Richard M. Hawkins Award. 

Co-authored 121 journal papers, 86 peer-reviewed; 3 chapters in books; 6 patents and inventions; 230+ conference contributions; 1270+ citations; h-index 22 (Google Scholar Citations), since 2004 h-index 18 (Scopus)

Scientific expertise includes:

  • Structure of glasses and amorphous thin films
  • Surface science in application to amorphous solids
  • Interaction of light and ionizing radiation with amorphous solids
  • Photodissolution of metals in glass matrix
  • Photolithography on glasses
  • E-beam nanolithography on glasses
  • X-ray photoelectron spectroscopy for amorphous solids
  • Nanofabrication (CVD for carbon nanotubes)
  • Thin film technologies

Current research interests include: atomic and electronic structure of non-oxide glasses and amorphous thin films (EXAFS, XANES, XPS, Raman, positron annihilation); structural dynamics in glasses; interaction of light and ionizing radiation with amorphous solids; surface science in application to solid state disordered media; gray scale photolithography and electron-beam nanostructuring on glasses; amorphous optical IR materials for micro- and nanophotonics.

Recent Research Projects:

  • 2017  – current: Project DMR-1725188 "MRI: Acquisition of a Positron Annihilation Lifetime Spectrometer for Enhanced Materials Characterization" – National Science Foundation, Co-PI
  • 2014 – current: Project DMR-1409160 "RUI: Radiation selectivity of photo-induced structural transformations in covalently bonded glassy thin films" – National Science Foundation, PI

Chapters in books:

  1. Jain H., Kovalskiy A., Vlcek M. Chalcogenide glass resists for lithography. In book: Chalcogenide glasses. Preparation, properties and applications / Eds. J.-L. Adam and X. Zhang. Oxford-Cambridge-Philadelphia-New Dehli: Woodhead Publishing. 2014, p. 562-596.
  2. Matkovskii A.O., Shpotyuk O.I., Vakiv M.M., Kovalskiy A.P. Radiation-stimulated changes of materials properties. Chalcogenide vitreous semiconductors. In book: Effect of ionizing irradiations on electronic materials / Ed. A.O. Matkovskii. Lviv: Svit. 1994, p. 158-180. (in Russian)
  3. Shpotyuk O.I., Kovalskiy A.P., Sawicki I.V., Matkovskii A.O. Photo- and radiation-chemical transformations in chalcogenide vitreous semiconductors. In book: Materials and devices for hologram registration / Ed. V.A. Barachevsky. Leningrad: Leningrad State Univ. 1986, p. 12-17. (in Russian).

Papers in peer-reviewed journals (86 papers, 11 of them in co-authorship with undergraduate students):

  1. Golovchak R., Nazabal V., Bureau B., Oelgoetz J., Kovalskiy A., Jain H. Chemical order in Ga or Sb modified germanium sulfide glasses around stoichiometry: High-resolution XPS and Raman studies. Journal of Non-Crystalline Solids, vol. 499, 2018, p. 237-244.
  2. Shpotyuk M., Kovalskiy A., Golovchak R., Shpotyuk O. Phenomenology of γ-irradiation-induced changes in optical properties of chalcogenide semiconductor glasses: A case study of binary arsenic sulfides. Journal of Non-Crystalline Solids, vol. 498, 2018, p. 315-322.
  3. Kovalskiy A., White M., Allen J., Golovchak R., Oelgoetz J., Shpotyuk O., Palka K., Slang S., Vlcek M. Photoresponse of inorganic-organic thin film composites based on chalcogenide glasses. AIP Conference Proceedings, vol. 1981, 2018, 020030 (1-4).
  4. Kovalskiy A., Vlcek M., Palka K., Buzek J., York-Winegar J., Oelgoetz J., Golovchak R., Shpotyuk O., Jain H. Structural origin of surface transformations in arsenic sulfide thin films upon UV-irradiation. Applied Surface Science, vol. 394, 2017, p. 604-612.
  5. Shpotyuk O., Bujnakova Z., Balaz P., Ingram A., Demchenko P., Kovalskiy A., Vlcek M., Shpotyuk Ya., Cebulski J., Dziedzic A. Nanostructurization effects in PVP-stabilized tetra-arsenic tetrasulfide As4S4 nanocomposites. Materials Chemistry and Physics, vol. 186, 2017, p. 251-260.
  6. Mugoni C., Jain H., Montrosi M., Montecchi M, Kovalskiy A., Siligardi C. Structural origin of electrical conductivity of copper lithium metaphosphate glasses. Journal of Non-Crystalline Solids, vol. 447, 2016, p. 91-97.
  7. Trimble J., Golovchak R., Oelgoetz J., Brennan C., Kovalskiy A. Structural characterisation of tin fluorophosphate glasses doped with Er2O3. Physics and Chemistry of Glasses – European Journal of Glass Science and Technology Part B, vol. 57 (1), 2016, p. 27-31.
  8. Shpotyuk O., Kovalskiy A., Trimble J., Vlcek M., Shpotyuk Ya., Koziukhin S. Intrinsic phase separation in low-temperature quenched arsenic trisulï¬de glass. Journal of Non-Crystalline Solids, vol. 430, 2015, p. 16-20.
  9. Cook J., Slang S., Golovchak R., Jain H., Vlcek M., Kovalskiy A. Structural features of spin-coated thin films of binary AsxS100–x chalcogenide glass system, Thin Solid Films, vol. 589, 2015, p. 642-648.
  10. Slang S., Palka K., Loghina L., Kovalskiy A., Jain H., Vlcek M. Mechanism of the dissolution of As–S chalcogenide glass in n-butylamine and its influence on the structure of spin coated layers. Journal of Non-Crystalline Solids, vol. 426, 2015, p. 126-131. 
  11. Golovchak R.,  Choi Y. G.,  Kozyukhin S.,  Chigirinsky Yu.,  Kovalskiy A.,  Xiong-Skiba P.,  Trimble J.,  Pafchek R.,  Jain H. Oxygen incorporation into GST phase-change memory matrix, Applied Surface Science, vol. 332, 2015, p. 533-541.
  12. Golovchak R., Lucas P., Oelgoetz J., Kovalskiy A., York-Winegar J., Saiyasombat C., Shpotyuk O., Feygenson M., Neuefeind J., Jain H. Medium range order and structural relaxation in As-Se network glasses through FSDP analysis, Materials Chemistry and Physics, vol. 153, 2015, p. 432-442.
  13. Xu S.W., Wang R.P., Luther-Davies B., Kovalskiy A., Miller A.C., Jain H. Chemical order in GexAsySe1-x+y glasses probed by high resolution X-ray photoelectron spectroscopy, Journal of Applied Physics, vol. 115 (8), 2014, 083518.
  14. Kovalskiy A., Golovchak R., Vlcek M., Jain. H. Electronic and atomic structure of amorphous thin films with high-resolution XPS: Examples of applications & limitations, Journal of Non-Crystalline Solids, vol. 377, 2013, p. 155-158. 
  15. Golovchak R., Kovalskiy A., Shpotyuk O., Jain H. Structural organization of As-rich selenide glasses. Solid State Communications, vol. 165, 2013, p. 22-26.
  16. Kovalskiy A., Vlcek M., Palka K., Golovchak R., Jain. H. Wavelength dependence of photostructural transformations in As2S3 thin films, Physics Procedia, vol. 44, 2013, p. 75-81. 
  17. Palka K., Vlcek M., Kovalskiy A. Study of As50Se50 thin film dissolution kinetics in amine based solutions, Physics Procedia, vol. 44, 2013, p. 114-119.
  18. York-Winegar J., Harper T., Brennan C., Oelgoetz J., Kovalskiy A., Structure of SnF2-SnO-P2O5 glasses, Physics Procedia, vol. 44, 2013, p. 159-165.
  19. Palumbo V., Kovalskiy A., Jain H., Huey B. D. Direct investigation of silver photodissolution dynamics and reversibility in arsenic trisulphide thin ï¬lms by atomic force microscopy, Nanotechnology, vol. 24 (12), 2013, 125706-1-7. 
  20. Choi Y. G., Kovalskiy A., Cheong B.-K., Jain H. Role of local structure in the phase change of GeTe films. Chemical Physics Letters, vol. 534, 2012, p. 58-61.
  21. Sati D., Kovalskiy A., Golovchak R., Jain H. Structure of SbGe40-xSe60 glasses around 2.67 average coordination number, Journal of Non-Crystalline Solids, vol. 358, 2012, p. 163-167.
  22. Golovchak R., Shpotyuk O., Iovu M., Kovalskiy A., Jain H. Topology and chemical order in AsxGexSe1-2x glasses: a high resolution X-ray photoelectron spectroscopy study, Journal of Non-Crystalline Solids, vol. 357, 2011, p. 3454-3460.  
  23. Golovchak R., Kozdras A., Shpotyuk O., Gorecki Cz., Kovalskiy A., Jain H. Temperature-dependent structural relaxation in As40Se60 glass, Physics Letters A, vol. 375, 2011, p. 3032–3036.
  24. Golovchak R., Kovalskiy A., Shpotyuk O., Jain H. In search of energy landscape for network glasses, Applied Physics Letters, vol. 98, 2011, p. 171905-1-3.
  25. Golovchak R., Shpotyuk O., Kozyukhin S., Shpotyuk M., Kovalskiy A., Jain H. Short-range order evolution in S-rich Ge–S glasses by X-ray photoelectron spectroscopy, Journal of Non-Crystalline Solids, vol. 357, 2011, p. 1797–1803.
  26. Takats V., Miller A. C., Jain H., Kovalskiy A., Kokenyesi S. Investigation of interdiffusion in Sb/As2S3 nano-layered structures by high-resolution X-ray photoelectron spectroscopy, Thin Solid Films, vol. 519 (10), 2011, p. 3437-3442.
  27. Koziukhin S., Golovchak R., Kovalskiy A., Shpotyuk O., Jain H. Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS, Semiconductors, vol. 45 (4), 2011, p. 423-426.
  28. Kovalskiy A., Ganjoo A., Khalid S., Jain H. Combined high-resolution XPS and EXAFS study of Ag photodissolution in a-As2S3 thin film, Journal of Non-Crystalline Solids, vol. 356 (44-49), 2010, p. 2332-2336.
  29. Zhang Y., Yang Y., Zheng J., Chen G., Cheng C., Hwang J. C. M., Ooi B. S., Kovalskiy A., Jain H. Effect of the interface glass on electrical performance of screen printed Ag thick-film contacts of Si solar cells. Thin Solid Films, vol. 518 (24), Suppl. 1 (2010), p. e111-e113. 
  30. Golovchak R., Shpotyuk O., McCloy J. S., Riley B. J., Windisch C.F., Sundaram S. K., Kovalskiy A., Jain H. Structural model of homogeneous As-S glasses derived from Raman spectroscopy and high-resolution XPS. Philosophical Magazine, vol. 90 (34), 2010, p. 4489–4501.
  31. Kovalskiy A., Vlcek M., Cech J., Heffner W. R., Waits C. M., Dubey M., Jain H. Chalcogenide glass e-beam and photo resists for ultrathin grayscale patterning. Journal of Micro/Nanolithography, MEMS, and MOEMS, vol. 8, 2009, p. 043012-1-11.
  32. Mitkova M., Kovalskiy A., Jain H., Sakaguchi Y. Effect of photo-oxidation on the photodiffusion of silver in germanium chalcogenide glasses. Journal of Optoelectronics and Advanced Materials, vol. 11, 2009, p. 1899-1906. 
  33. Kovalskiy A., Jain H., Mitkova M. Evolution of chemical structure during silver photodiffusion into chalcogenide glass thin films. Journal of Non-Crystalline Solids, vol. 355, 2009, p. 1924-1929.
  34. Golovchak R., Shpotyuk O., Koziukhin S., Kovalskiy A., Miller A.C., Jain H. Structural paradigm of Se-rich Ge-Se glasses by high-resolution X-ray photoelectron spectroscopy. Journal of Applied Physics, vol. 105, 2009, p. 103704-1-7. 
  35. Kovalskiy A., Neilson J.R., Miller A.C., Miller F.C., Vlcek M., Jain H. Comparative study of electron- and photo-induced structural transformations on the surface of As35S65 amorphous thin films. Thin Solid Films, vol. 516, 2008, p. 7511-7518.
  36. Kovalskiy A., Miller A., Jain H., Mitkova M. In-situ measurements of X-ray induced silver diffusion into Ge30Se70 thin film. Journal of the American Ceramic Society, vol. 91 (3), 2008, p. 760-765.
  37. Golovchak R., Shpotyuk O., Kovalskiy A., Miller A., Cech J., Jain H. Coordination defects in bismuth-modified arsenic selenide glasses: High-resolution X-ray photoelectron spectroscopy measurements. Physical Review B, vol. 177, 2008, p. 172201-1-4. (Published also in Virtual Journal of Nanoscale Science & Technology).
  38. Golovchak R., Shpotyuk O., Kozdras A., Vlcek M., Bureau B., Kovalskiy A., Jain H. Long-term physical ageing in As-Se glasses with short chalcogen chains. Journal of Physics: Condensed Matter, vol. 20 (24), 2008, p. 245107-1-7.
  39. Shpotyuk O., Golovchak R., Jain H., Kovalskiy A. Radiation-induced functionality of chalcogenide glasses probed by high-resolution XPS. Physics and Chemistry of Glasses: European Journal of Glass Science and Technology: Part B, vol. 49, 2008, p. 314-316.
  40. Golovchak R., Kovalskiy A., Miller A., Jain H., Shpotyuk O. Structure of Se-rich As-Se glasses by high-resolution photoelectron spectroscopy. Physical Review B, vol. 76 (12), 2007, p. 125208-1-7.
  41. Kovalskiy A., Jain H., Neilson J.R., Vlcek M., Waits C.M., Churaman W., Dubey M. On the mechanism of gray scale patterning of Ag-containing As2S3 thin films. Journal of Physics and Chemistry of Solids, vol. 68, 2007, p. 920-925.
  42. Neilson J.R., Kovalskiy A., Vlcek M., Jain H., Miller F. Fabrication of nano-gratings in arsenic sulphide films. Journal of Non-Crystalline Solids, vol. 353, 2007, p. 1427-1430. 
  43. Shpotyuk O., Kovalskiy A., Golovchak R., Zurawska A., Jain H. Radiation-induced defects in chalcogenide glasses characterized by optical spectroscopy, XPS and PALS methods. Physica Status Solidi C, vol. 4, 2007, p. 1147-1150. 
  44. Balitska V., Kovalskiy A., Shpotyuk O., Vakiv M. On the instability effects in radiation-sensitive chalcogenide glasses. Radiation Measurements, vol. 42, 2007, p. 941-943.
  45. Shpotyuk O., Vakiv M., Butkiewicz B., Kovalskiy A., Golovchak R. On the problem of relaxation for radiation-induced optical effects in some ternary chalcogenide glasses. Semiconductor Physics, Quantum Electronics & Optoelectronics, vol. 10 (3), 2007, p. 23-27.
  46. Kovalskiy A., Jain H., Miller A., Golovchak R., Shpotyuk O. A study of reversible γ-induced structural transformations in vitreous Ge23.5Sb11.8S64.7 by high resolution X-ray photoelectron spectroscopy. Journal of Physical Chemistry B, vol. 110, 2006, p. 22930-22934.
  47. Kovalskiy A., Vlcek M., Jain H., Fiserova A., Waits C.M., Dubey M. Development of chalcogenide glass photoresists for gray scale lithography. Journal of Non-Crystalline Solids, vol. 352, 2006, p. 589-594.
  48. Jain H., Kovalskiy A., Miller A. An XPS study of the early stages of silver photodiffusion in Ag/a-As2S3 films. Journal of Non-Crystalline Solids, vol. 352, 2006, p. 562-566.
  49. Shpotyuk O., Kovalskiy A., Filipecki J., Kavetskyy T., Popescu M. Positron annihilation lifetime spectroscopy as experimental probe of free volume concepts in network glasses. Physics and Chemistry of Glasses: European Journal of Glass Science and Technology: Part B, vol. 47, 2006, p. 131-135.
  50. Kozdras A., Filipecki J., Hyla M., Shpotyuk O., Kovalskiy A., Szymura S. Nanovolume positron traps in glassy-like As3Se3. Journal of Non-Crystalline Solids, vol. 351, 2005, p. 1077-1081.
  51. Shpotyuk O., Kovalskiy A., Kavetskyy T., Golovchak R. Threshold restoration effects in ï§-irradiated chalcogenide glasses. Journal of Non-Crystalline Solids, vol. 351, 2005, p. 993-997.
  52. Kavetskyy T., Shpotyuk O., Kovalskiy A., Tsmots V. Structural-chemical approach for compositional dependences of ï? ï§-induced optical effects in chalcogenide glasses of Ge-Sb-S system. Journal of Optoelectronics and Advanced Materials, vol. 5, 2005, p. 2299-2308.
  53. Kozdras A., Shpotyuk O., Kovalskiy A., Filipecki J. Modified positron annihilation model for glassy-like As2Se3. Acta Physica Polonica A, vol. 107, 2005, p. 832-836.
  54. Kovalskiy A. Compositional trends of radiation induced effects in ternary systems of chalcogenide glasses. Radiation Effects & Defects in Solids, vol. 158, 2003, p. 391-397.
  55. Shpotyuk O., Kovalskiy A., Filipecki J., Hyla M., Kozdras A. A nanoscale characterisation of extended defects in glassy-like As2Se3 semiconductors with PAL technique. Physica B, vol. 340-342, 2003, p. 960-964.
  56. Shpotyuk O., Kovalskiy A., Kavetskyy T., Golovchak R. Post-irradiation thermally stimulated recovering of some ternary chalcogenide glasses. Journal of Optoelectronics and Advanced Materials, vol. 5, No 5, 2003, p. 1169-1179.
  57. Shpotyuk O., Kovalskiy A., Kavetskyy T., Golovchak R., Popescu M. Chemical interaction of chalcogenide vitreous semiconductors with absorbed impurities induced by ï§-irradiation. Journal of Optoelectronics and Advanced Materials, vol. 5, No 5, 2003, p. 1181-1185.
  58. Filipecki J., Shpotyuk O.I., Kozdras A., Kovalskiy A. Positron lifetime study of native vacancy-like defects in chalcogenide glasses. Radiation Physics and Chemistry, vol. 68, No 3-4, 2003, p. 557-559.
  59. Balitska V., Golovchak R., Kovalskiy A., Skordeva E., Shpotyuk O. Effect of Co60 ï§-irradiation on the optical properties of As-Ge-S glasses. Journal of Non-Crystalline Solids, vol. 326-327, 2003, p. 130-134.
  60. Shpotyuk O., Golovchak R., Kovalsky A., Kavetskyy T. Time and temperature stability of radiation-induced changes in optical properties of ternary chalcogenide glassy semiconductor systems. Functional Materials, vol. 10, No 2, 2003, p. 317-322. 
  61. Kovalskiy A., Kavetskyy T., Plewa J., Shpotyuk O. Interpretation of radiation-induced phenomena in chalcogenide glasses of Ge–Sb–S system using free volume and covalent chemical bonds concepts. Solid State Phenomena, vol. 90-91, 2003, p. 241-246.
  62. Shpotyuk O., Filipecki J., Kozdras A., Kovalskiy A. Coordination positron-trapping centers in vitreous chalcogenide semiconductors. Physica Status Solidi C, vol. 0, No 2, 2003, p. 795-798.
  63. Shpotyuk O., Filipecki J., Golovchak R., Kovalskiy A., Hyla M. Application of positron annihilation lifetime technique for ï§-irradiation stresses study in chalcogenide vitreous semiconductors. Advanced Engineering Materials, 2002, v. 4, No 8, p. 571-574.
  64. Shpotyuk O., Golovchak R., Kovalskiy A., Pamukchieva V., Skordeva E., Arsova D. On the mechanism of radiation-induced optical effects in vitreous As2S3-GeS2. Ukrainian Journal of Physical Optics, 2002, v. 3, No 2, p. 134-143. 
  65. Shpotyuk O., Kovalskiy A. Compositional trends in radiation-optical properties of chalcogenide glasses. Journal of Optoelectronics and Advanced Materials, 2002, v. 4, No. 3, p. 751-762.
  66. Shpotyuk O., Filipecki J., Hyla M., Kovalskiy A., Golovchak R. Coordination defects in chalcogenide amorphous semiconductors studied by positron annihilation lifetime. Physica B, 2001, v. 308-310, p. 1011-1014.
  67. Shpotyuk O., Kovalskiy A., Mrooz O., Shpotyuk L., Pekhnyo V., Volkov S. Technological modification of spinel-based CuxNi1-x-yCo2yMn2-yO4 ceramics. Journal of the European Ceramic Society, 2001, v.21, p. 2067-2070.
  68. Mrooz O., Kovalski A., Pogorzelska J., Shpotyuk O., Vakiv M., Butkiewicz B., Maciak J. Thermoelectrical degradation processes in NTC thermistors for in-rush current protection of electronic circuits. Microelectronics Reliability, 2001, v. 41, p. 773-777.
  69. Butkiewicz B., Golovchak R., Kovalskiy A., Shpotyuk O., Vakiv M. On the problem of relaxation for radiation-induced optical effects in some ternary chalcogenide glasses. Radiation Effects & Defects in Solids, 2001, v. 153, p. 211-219.
  70. Shpotyuk O.I., Filipecki J., Golovchak R.Ya., Kovalskiy A.P., Hyla M. Radiation-defects in amorphous As-Ge-S studied by positron annihilation techniques. Journal of Optoelectronics and Advanced Materials, 2001, v. 3, No 2, p. 329-332.
  71. Shpotyuk O.I., Kavetsky T.S., Kovalskiy A.P., Lutciv R.V., Pamukchieva V.D. Radiation-induced changes of optical transmittance in vitreous semiconductors of GexSb40-xS60 system. Ukrainian Journal of Physics, 2001, v. 46, No 4, p. 495-498.
  72. Kovalskiy A. Peculiarities of ï§-induced optical effects in ternary systems of amorphous chalcogenide semiconductors. Journal of Optoelectronics and Advanced Materials, 2001, v. 3, No 2, p. 323-327.
  73. Shpotyuk O., Hadzaman I., Mrooz O., Kovalskiy A., Vakiv M. Microscopic characterization of manganese-containing oxide ceramics for current protection of electric circuits. Practical Metallography, 2001, v. 32, p. 209-212.
  74. Shpotyuk O.I., Golovchak R.Ya., Kovalskiy A.P., Vakiv M.M., Pamukchieva V.D., Arsova D.D., Skordeva E.R. Radiation optical effects in As2S3-GeS2 semiconducting glasses. Physics and Chemistry of Glasses, 2001, v. 42, No 2, p. 95-98.
  75. Shpotyuk O., Vakiv M., Kovalskiy A.P., Skordeva E., Vateva E., Pamukchieva V., Golovchak R., Lutciv R. Radiation-induced effects in Ge-As-S chalcogenide glasses. Glass Physics and Chemistry, 2000, v. 26, No 3, p. 374-380. 
  76. Skordeva E., Arsova D., Pamukchieva V., Vateva E., Golovchak R., Kovalskiy A.P., Shpotyuk O. ï§-induced changes in Ge-As-S glasses. Journal of Optoelectronics and Advanced Materials, 2000, v.2, No 3, p. 259-266.
  77. Vynnik I.B., Dunets B.V., Kovalsky A.P. Ceramic humidity sensitive elements with intelligent tester of informative parameters. Functional Materials, 2000, v. 7, no 2, p. 319-322.
  78. Shpotyuk O.I., Golovchak R.Ya., Kavetsky T.S., Kovalskiy A.P., Vakiv M.M. Radiation-optical effects in glassy Ge-As(Sb)-S systems. Nuclear Instruments and Methods in Physics Research Section B - Beam Interaction with Materials & Atoms, 2000, v. 166-167, p. 517-520.
  79. Kovalskiy A.P., Shpotyuk O.I., Hadzaman I.V., Mrooz O.Ya., Vakiv M.M. The influence of §-irradiation on electrophysical properties of spinel-based oxide ceramics. Nuclear Instruments and Methods in Physics Research B - Beam Interaction with Materials & Atoms, 2000, v. 166-167, p. 289-292.
  80. Kavetskyy T.S., Kovalskiy A.P., Pamukchieva V.D., Shpotyuk O.I. IR impurity absorption in Sb2S3-GeS2(Ge2S3) chalcogenide glasses. Infrared Physics & Technology, 2000, v. 41, p. 41-45.
  81. Shpotyuk O.I., Kovalskiy A.P., Skordeva E., Vateva E., Arsova D., Golovchak R.Ya., Vakiv M.M. Effect of gamma-irradiation on the optical properties of GexAs40-xS60 glasses. Physica B. Condensed Matter, 1999, v.271, p. 242-247.
  82. Shpotyuk O.I., Skordeva E., Golovchak R.Ya., Pamukchieva V., Koval–skii A.P. Radiation-stimulated changes of transmission in As2S3-Ge2S3 chalcogenide glasses. Journal of Applied Spectroscopy, 1999, v.66, No 5, p. 657-660. 
  83. Shpotyuk O.I., Vakiv M.M., Matkovskii A.O., Kovalski A.P. Radiation-induced paramagnetic centers in amorphous chalcogenide semiconductors. Opto-Electronics Review, 1997, V.5, No 1, p. 39-41.
  84. Hadzaman I.V., Kovalsky A.P., Mrooz O.Ya., Shpotyuk O.I. Thermal modification of ceramic composites based on manganese-containing cube spinels. Materials Letters, 1996, V.29, p.195-198.
  85. Shpotyuk O.I., Matkovskii A.O., Kovalsky A.P., Vakiv M.M.Radiation-induced changes of amorphous As2S3 physical properties. Radiation Effects and Defects in Solids, 1995, v. 133, No 1, p. 1-4.
  86. Shpotyuk O.I., Kovalsky A.P., Vakiv M.M., Mrooz O.Ya. Reversible radiation effects in vitreous As2S3. 1. Changes of physical properties. Physica Status Solidi A, 1994, v. 144, No 2, p. 277-283.