Characterization of Atomic Layer Deposited Films as Diffusion Barriers for Silver Art Objects Amy Marquardt 1 , Eric M. Breitung 1 , Terry Drayman-Weisser 2 , Glenn Gates 2 , Gary W. Rubloff 1 , and R. J. Phaneuf 1, * (1) Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA (2) The Walters Art Museum, 600 N. Charles Street, Baltimore, MD 21201,USA * corresponding author: phaneuf@umd.edu Abstract In this article we report on the characterization of atomic layer deposited (ALD) films on silver alloy objects, both with regard to film porosity, which potentially limits their effectiveness as tarnish barriers, and with regard to color change upon deposition, which affects their visual appearance. We find that the porosity of ALD alumina films decreases with thickness, and shows no clear dependence on surface preparation, nor on multiple ALD oxide layering. We also find that the optimized structures for minimizing color change are sensitive to the composition of the alloy, and must be tuned accordingly. Introduction Atomic layer deposition (ALD), a technique developed for applications in microelectronics, is finding new and interesting applications in a variety of fields. Inspired by interest in the application of new technologies to cultural heritage conservation [Madsen2011, Adriaens2010, Baglioni2008, Giorgi2010, Melcher2010,Pouli2010, Prati2010, Targowski2010] we have recently begun investigation of the use of ALD in creating protective coatings for art objects crafted from heritage metals [Marquardt2013a,b, Breitung2010]. Art conservation places multiple requirements on corrosion-barrier films which might serve as replacements for the presently employed polymeric coatings, such as nitrocellulose. Among these requirements are higher effectiveness than polymeric coatings in impeding corrosion of the underlying object, minimal change of the appearance when coated, ease of application, and reversibility. ALD has been demonstrated to produce films of extremely high conformality [Banarjee2009, Perez2008] and continuity [Carcia2010], both important considerations in such an application. Elsewhere we have presented results analyzing of the performance of ALD-based films in meeting the requirements for the protection of silver art objects [Marquardt2013a,b, Breitung2010], including their long effective lifetimes, and high degree of reversibility. In this article we concentrate on two main aspects of ALD-tarnish barrier films not previously reported on, continuity of the films and their visual appearance. 10.1149/05810.0277ecst ©The Electrochemical Society ECS Transactions, 58 (10) 277-286 (2013) 277 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.215.112.108 Downloaded on 2015-07-15 to IP