Interface structure in nanoscale multilayers near continuous-to-discontinuous regime

Journal Article · Thu Jul 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4959250· OSTI ID:22597789

Pradhan, P. C.; Majhi, A. ^[1]; Rajput, P.; Biswas, A.; Jha, S. N.; Bhattacharyya, D.; Sahoo, N. K. ^[2]; Shukla, D. K.; Phase, D. M. ^[3]; Rai, S. K. ^[4]

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1. Raja Ramanna Centre for Advanced Technology, HBNI, Indore 452013 (India)
2. Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)
3. UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India)
4. Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

Interfacial atomic diffusion, reaction, and formation of microstructure in nanoscale level are investigated in W/B{sub 4}C multilayer (ML) system as functions of thickness in ultrathin limit. Hard x-ray reflectivity (XRR) and x-ray diffuse scattering in conjunction with x-ray absorption near edge spectroscopy (XANES) in soft x-ray and hard x-ray regimes and depth profiling x-ray photoelectron spectroscopy (XPS) have been used to precisely evaluate detailed interfacial structure by systematically varying the individual layer thickness from continuous-to-discontinuous regime. It is observed that the interfacial morphology undergoes an unexpected significant modification as the layer thickness varies from continuous-to-discontinuous regime. The interfacial atomic diffusion increases, the physical density of W layer decreases and that of B{sub 4}C layer increases, and further more interestingly the in-plane correlation length decreases substantially as the layer thickness varies from continuous-to-discontinuous regime. This is corroborated using combined XRR and x-ray diffused scattering analysis. XANES and XPS results show formation of more and more tungsten compounds at the interfaces as the layer thickness decreases below the percolation threshold due to increase in the contact area between the elements. The formation of compound enhances to minimize certain degree of disorder at the interfaces in the discontinuous region that enables to maintain the periodic structure in ML. The degree of interfacial atomic diffusion, interlayer interaction, and microstructure is correlated as a function of layer thickness during early stage of film growth.

• OSTI ID: 22597789
• Journal Information: Journal of Applied Physics, Vol. 120, Issue 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
ABSORPTION SPECTROSCOPY
BORON CARBIDES
DIFFUSE SCATTERING
DIFFUSION
FILMS
HARD X RADIATION
INTERFACES
LAYERS
MICROSTRUCTURE
MORPHOLOGY
NANOSTRUCTURES
REFLECTIVITY
SOFT X RADIATION
THICKNESS
TUNGSTEN COMPOUNDS
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTROSCOPY