Ductility maximum and weakening and strengthening phenomena in two-phase metallic materials

Movchan, B. A.; Demchishin, A.V.; Badilenko, G.F.

doi:10.1007/bf01524637

Cited by 97 publications

(133 citation statements)

References 2 publications

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“…However, detailed descriptions of the structure of metallic films, including samples prepared under similar conditions, are found in Refs. [29][30][31][32][33]. The film thickness, measured by an Alfa Step profilometer, is in the 0.4-4.8 m range.…”

Section: A Sample Preparationmentioning

confidence: 99%

Coefficient of thermal expansion and elastic modulus of thin films

Lima

Lacerda

Vilcarromero

et al. 1999

Journal of Applied Physics

134

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The coefficient of thermal expansion ͑CTE͒, biaxial modulus, and stress of some amorphous semiconductors ͑a-Si:H, a-C:H, a-Ge:H, and a-GeC x :H͒ and metallic ͑Ag and Al͒ thin films were studied. The thermal expansion and the biaxial modulus were measured by the thermally induced bending technique. The stress of the metallic films, deposited by thermal evaporation ͑Ag and Al͒, is tensile, while that of the amorphous films deposited by sputtering ͑a-Si:H, a-Ge:H, and a-GeC x :H͒ and by glow discharge (a-C:H) is compressive. We observed that the coefficient of thermal expansion of the tetrahedral amorphous thin films prepared in this work, as well as that of the films reported in literature, depend on the network strain. The CTE of tensile films is smaller than that of their corresponding crystalline semiconductors, but it is higher for compressive films. On the other hand, we found out that the elastic biaxial modulus of the amorphous and metallic films is systematically smaller than that of their crystalline counterparts. This behavior stands for other films reported in the literature that were prepared by different techniques and deposition conditions. These differences were attributed to the reduction of the coordination number and to the presence of defects, such as voids and dangling bonds, in amorphous films. On the other hand, columnar structure and microcrystallinity account for the reduced elasticity of the metallic films.

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Section: A Sample Preparationmentioning

confidence: 99%

Coefficient of thermal expansion and elastic modulus of thin films

Lima

Lacerda

Vilcarromero

et al. 1999

Journal of Applied Physics

134

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“…1. The vertical dashed lines represent the limits of the Movchan-Demchishin-Thornton 32,33,48 zone scheme, where the depositions with temperatures lower than 30% of the melting 49 correspond to the first (Z 1 ) and energy enhanced (Z T ) zones, while higher temperatures (T s > 500 C) correspond to the second zone (Z 2 ). An initial slight increase in thickness (up to T s ¼ 300 C) and a subsequent continuous decrease (500 C T s 1000 C) were observed.…”

Section: Resultsmentioning

confidence: 99%

Effects of substrate temperature, substrate orientation, and energetic atomic collisions on the structure of GaN films grown by reactive sputtering

Schiaber

Leite

Bortoleto

et al. 2013

Journal of Applied Physics

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Growth stresses and cracking in GaN films on (111) The combined effects of substrate temperature, substrate orientation, and energetic particle impingement on the structure of GaN films grown by reactive radio-frequency magnetron sputtering are investigated. Monte-Carlo based simulations are employed to analyze the energies of the species generated in the plasma and colliding with the growing surface. Polycrystalline films grown at temperatures ranging from 500 to 1000 C clearly showed a dependence of orientation texture and surface morphology on substrate orientation (c-and a-plane sapphire) in which the (0001) GaN planes were parallel to the substrate surface. A large increase in interplanar spacing associated with the increase in both a-and c-parameters of the hexagonal lattice and a redshift of the optical bandgap were observed at substrate temperatures higher than 600 C. The results showed that the tensile stresses produced during the film's growth in high-temperature deposition ranges were much larger than the expected compressive stresses caused by the difference in the thermal expansion coefficients of the film and substrate in the cool-down process after the film growth. The best films were deposited at 500 C, 30 W and 600 C, 45 W, which corresponds to conditions where the out diffusion from the film is low. Under these conditions the benefits of the temperature increase because of the decrease in defect density are greater than the problems caused by the strongly strained lattice that occurr at higher temperatures. The results are useful to the analysis of the growth conditions of GaN films by reactive sputtering. V C 2013 AIP Publishing LLC.

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“…There has been a lot of experimental work on the grain structure of vapour-deposited metallic films. For thick deposits and high deposition rates (R > 100A s-'), three temperature zones have been found, each of which is characterized by a different type of microstructure [9,10]. For Ts < 0.3TM (zone I), film growth proceeds by ballistic aggregation and the internal structure is porous and contains a high dislocation density.…”

Section: Discussionmentioning

confidence: 99%

“…The crucial influence of T s on the microstructure of thin metallic films has been observed for many film/substrate combinations [8][9][10]. An empirical scheme was proposed, in which the type of grain growth and microstructure in vapour-deposited films is classified in different zones depending on the reduced temperature Ts/TM (TM, melting temperature) [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…An empirical scheme was proposed, in which the type of grain growth and microstructure in vapour-deposited films is classified in different zones depending on the reduced temperature Ts/TM (TM, melting temperature) [8][9][10]. This structure-zone model has been supported by computer simulations [11,12] and has become a general classification scheme for the study of many film properties including hardness, corrosion and electrical conductivity.…”

Section: Introductionmentioning

confidence: 99%

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Effect of substrate temperature on the microstructure of thin niobium films

1994

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Niobium films with constant thickness have been deposited on sapphire (1120) by electron-beam evaporation at different substrate temperatures ( 150 °C ~< T s ~< 750 °C). The samples were characterized by X-ray diffraction and resistivity measurements. X-ray reflectivity shows that all films are covered with an oxide layer of about 20 A in ambient atmosphere. The (110) texture at high Ts decreases towards lower Ts, accompanied by an increasing surface roughness. Below T s = 350 °C the grain size in the growth direction becomes smaller than the film thickness and a relaxation of intrinsic stress is observed. A transition from a columnar growth structure to a fine grained microstructure is inferred. The change of the microstructure with T s is probably due to the temperature dependent grain boundary mobility during the deposition process.

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Ductility maximum and weakening and strengthening phenomena in two-phase metallic materials

Cited by 97 publications

References 2 publications

Coefficient of thermal expansion and elastic modulus of thin films

Coefficient of thermal expansion and elastic modulus of thin films

Effects of substrate temperature, substrate orientation, and energetic atomic collisions on the structure of GaN films grown by reactive sputtering

Effect of substrate temperature on the microstructure of thin niobium films

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