Investigation of mechanical properties of superionic crystals and films Cu<sub>6</sub>PS<sub>5</sub>Br(І) by micro- and nanoindentation method
DOI:
https://doi.org/10.24144/2415-8038.2017.41.58-67Keywords:
nano- and micro-indentation, superionic materials, Cu6PS5Br(І), dislocations, hardness, indentation size effects, Stress-Gradient Plasticity ModelAbstract
Purpose. The purpose of this work is the investigation of mechanical characteristics of superoinic crystals Cu6PS5Br(І) and Cu6PS5І-based thin films deposited and to determine of indentation size effects.
Methods. The measurements of hardness H and Young's modulus E were performed using a CSM Instruments NHT-TTX nanohardness meter at a temperature of 293 K. The measurements of mikrohardness were performed using a PMT-3 mikrohardness meter with Vickers pyramid.
Results. The nanohardness and Young's modulus of Cu6PS5Br(І) crystals and films were measured by nanoindentation method with harmonic modulation force. In dependences H(h) and E(h) reveal features that indicate a significant change in mechanical characteristics of crystals in the nanoregion. Obtained dependences have been approximated in the framework of strain gradient plasticity theory. The mechanical parameters of Cu6PS5І films have been studied depending on the penetration depth of indenter during nanoindentationt. The effect of the influence substrate on the interaction between a film and indenter in nanocontact region is shown.
Conclusions. It is shown that deformation of Cu6PS5Br(І) crystals in a nano-region is mostly elastic and can be interpreted in Hertz's theory. The plastic deformation of crystals in the micro-region has a dislocation mechanism. The dimensional effects are explained within the framework of strain gradient plasticity theories. Dimensional effects are due to the formation during the indentation of circular loops of geometrically necessary dislocations with Burgers vectors perpendicular to the plane surface of the crystal. The reduction in the microhardness of Cu6PS5І-based thin with increasing copper content is due to structure.
References
Студеняк І.П., Краньчец M. Процеси розупорядкування в суперіонних провідниках зі структурою аргіродита. – Ужгород: Говерла, 2007. – 208 с.
Kuhs W. F., Nitsche R., Scheunemann K. Vapour growth and lattice data of new compounds with icosahedral structure of the type Cu6PS5Hal (Hal=Cl,Br,I) // Mat. Res. Bull. – 1976. – Vol.11, №9. – P. 1115-1124.
Студеняк И.П., Вайткус Р.А., Дьордяй В.С., Кеженис А.П., Микученис А.П., Панько В.В., Ковач Д.Ш., Стефанович В.А., Орлюкас А.С., Борец А.Н., Сливка В.Ю. Фазовые переходы в монокристаллах Cu6PS5I // Физ. тверд. тела. – 1986. – T. 28, №3. – C. 2555-2557.
Головин Ю.И. Наноиндентирование и механические свойства твердых тел в субмикрообъемах, тонких приповерхностных слоях и пленках. // ФТТ. – 2008. – Т.50, №12. – С. 2113-2142.
Головин Ю.И. Наноиндентирование и его возможности. – Москва: Машиностроение, 2009, 312 с.
Milman Yu.V., Golubenko A.A., Dub S.N. Indentation size effect in nanohardness. // Acta Materialia. – 2011.¬– 59. – P. 7480–7487.
Giannakopoulos A.E., Suresh S. Determination of elastoplastic properties by instrumented sharp indentation. // Scripta mater. – 1999. – V. 40, N 10, – P. 1191-1198.
Tsui T.Y., Pharr G.M. Substrate effects on nanoindentation mechanical property measurement of soft films on hard substrates. // J. Mater. Res. – 1999. – 14. – P. 292-301.
Mason J. K., Lund A. C., Schuh C. A. Determining the activation energy and volume for the onset of plasticity during nanoindentation. // Physical review B 73. – 2006. – P. 054102:1-14.
Min Lai, Xiaodong Zhang and Fengzhou Fang. Nanoindentation-induced phase transformation and structural deformation of monocrystalline germanium: a molecular dynamics simulation investigation. // Nanoscale Research Letters. – 2013. – V. 8, – Р. 353:1-9.
Ashby M. F. The deformation of plastically non-homogeneous materials. // Philos. Mag. – 1970. – V. 21. – P. 399–424.
Gao, H., Huang, Y., Nix, W. D., Hutchinson J. W. Mechanism Based Strain Gradient Plasticity – I. Theory. // J. Mech. Phys. Solids – 1999. – 47. –P. 1239–1263.
Nix W. D., Gao H., Indentation Size Effects in Crystalline Materials: A Law for Strain Gradient Plasticity, J. Mech. Phys. Solids – 1998. – V. 46, (N3). – P. 411–425.
Matthew R. Begley and John W. Hutchinson. The mechanics of size-dependent indentation. // J. Mech. Phys. Solids. –1998. – V. 35, No. 9. – P. 2049-2068.
Zong Z., Lou J., Adewoye O. O., Elmustafa A. A., Hammad F., Soboyejo W. O. Indentation Size Effects in the Nano and Microhardness of FCC Single Crystal Metals. // Materials and Manufacturing Processes – 2007. – V. 22. – P. 228–237.
Биланич B.С., Lofaj F., Flachbart К., Csach K., Кузьма В.В., Ризак В.М. Наноиндентирование аморфных пленок системы Ge-As-Se. // Физика твердого тела – 2014. – T. 56, вып. 6. – C. 1118-1122.
Studenyak I., Rybak S., Bendak A., Izai V., Guranich P., Kúš P., Mikula M. Structural disordering studies of Cu6PS5I-based thin films deposited by magnetron sputtering. // EPJ Web of Conferences –2017. – V. 133. – P. 02002:1-3.
Studenyak I.P., Bendak A.V., Izai V.Yu., Guranich P.P., Kúš P., Mikula M., Grančič B., Zahoran M., Greguš J., Vincze A., Roch T., Plecenik T. Electrical and optical parameters of Cu6PS5I-based thin films deposited using magnetron sputtering. // Semiconductor Physics, Quantum Electronics & Optoelectronics – 2016. – V. 9, N 1. – P. 79-83.
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