Gangopadhyay. 31 Metallic Alloy Nanoparticles and Metal-Semiconductor Nanomaterials NanoWorld Journal Review Article Open Access https://doi.org/10.17756/nwj.2018-058 Parthasarathi Gangopadhyay * Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India * Correspondence to: Dr. Parthasarathi Gangopadhyay, PhD Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 Tamil Nadu, India Tel: +91-44-27480085 E-mail: pganguly@igcar.gov.in Received: June 15, 2018 Accepted: October 08, 2018 Published: October 10, 2018 Citation: Gangopadhyay P. 2018. Metallic Alloy Nanoparticles and Metal-Semiconductor Nanomaterials. NanoWorld J 4(3): 31-42. Copyright: © 2018 Gangopadhyay. Tis is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY) (http:// creativecommons.org/licenses/by/4.0/) which permits commercial use, including reproduction, adaptation, and distribution of the article provided the original author and source are credited. Published by United Scientifc Group Abstract While bridging the gap between the atomic structures and bulk matters, nanomaterials are of great interests for fundamental understanding as well as for diferent application perspectives. In this article, it is proposed to provide a review regarding various synthesis processes of nanomaterials, growth mechanisms and a range of experimental techniques to discuss remarkable properties of materials at the nanoscale dimensions. Equilibrium (ambient or vacuum thermal annealing) as well as non-equilibrium (for example, utilizing ion-beams) methods are elaborated for the processing of nanomaterials. Here, nanomaterials stand for species of metal nanoparticles, bimetallic alloy nanoparticles or composite materials of metal nanoparticles in diferent oxide semiconductors. Akin to the pure metal nanoparticles, alloy metal nanoparticles exhibit exciting optical responses. For example, surface-plasmon resonance frequencies of bimetallic alloy nanoparticles are tunable in controlled fashions through the variation of alloy compositions. Metal nanoparticles in semiconductors are discussed to elucidate examples of quasi-particle interactions between plasmons and excitons in the composite as well as interesting photoluminescence properties of the nanomaterials. Termal stability of semiconductors and growth of the nanoscale metal particles in the composites are found to play crucial roles in this regard. Depending on the growth of metal nanoparticles, for instance, photoluminescence intensity of semiconductors is observed to be enhanced or quenched in the metal- semiconductor composite nanostructures. Keywords Nanomaterials, Ion beam, Termal annealing, Optical, Photoluminescence, XPS, XRD List of Abbreviations SPR: Surface-plasmon resonance; PL: Photoluminescence; XPS: X-ray photoelectron spectroscopy; GIXRD: Grazing incidence X-ray difraction; HRTEM: High-resolution transmission electron microscopy; IBS: Ion-beam sputtering Introduction At nanoscale dimensions, metals, bimetallic alloys and semiconductors (quantum dots) exhibit remarkable materials properties which are completely unknown in their bulk counterparts. As an outcome, great lots of research interests are shown from diferent perspectives: materials synthesis, fundamental understanding as well as from application point of view. Nanomaterials, as we know, are no way diferent compared to the parent phase of materials except