Investigation of the foil structure and corrosion mechanisms of modern Zwischgold using advanced analysis techniques

DOI: 10.1016/j.culher.2017.12.005

Authors: Qing Wu (Bern University of Applied Sciences (BUAS) – Bern University of the Arts (BUA)) , Karolina Soppa (Bern University of Applied Sciences (BUAS) – Bern University of the Arts (BUA)) , Nadim Scherrer (Bern University of Applied Sciences (BUAS) – Bern University of the Arts (BUA)) , Benjamin Watts (Paul Scherrer Institute (PSI)) , Tadahiro Yokosawa (Friedrich-Alexander University Erlangen-Nürnberg (FAU)) , Laetitia Bernard (Swiss National Laboratories of Material Science and Technology (Empa)) , Tohru Araki (Diamond Light Source) , Max Döbeli (Swiss Federal Institute of Technology in Zurich (ETHZ)) , Markus Meyer (Friedrich-Alexander University Erlangen-Nürnberg (FAU)) , Erdmann Spiecker (Friedrich-Alexander University Erlangen-Nürnberg (FAU)) , Rainer H. Fink (Friedrich-Alexander University Erlangen-Nürnberg (FAU))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Cultural Heritage

State: Published (Approved)
Published: January 2018
Diamond Proposal Number(s): 15595

Abstract: Zwischgold is a two-sided metal foil made by adhering a gold leaf over a silver leaf to present a gold surface while using less gold than gold foils. Corroded Zwischgold surfaces appear dark, accompanied by gloss loss and possible mechanical stability issues. Zwischgold applied artefacts are commonly found in museums and churches across Europe and they currently face an uncertain future as conservators have little knowledge to base conservation treatments on. We present a comprehensive material analysis of Zwischgold models through advanced characterization techniques including focused ion beam coupled with scanning electron microscopy (FIB-SEM), transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM), time-of-flight secondary ion mass spectrometry (TOF-SIMS)and Rutherford backscattering spectrometry (RBS). Complementary information on the foil thickness,sharpness of the gold-silver interface, gold purity, and the formation as well as distribution of corrosion products on Zwischgold models have been obtained, representing a starting point for understanding themorphology and the long-term chemistry of Zwischgold artefacts.

Journal Keywords: Zwischgold; Interdiffusion; Gold; Silver; Corrosion; Conservation

Diamond Keywords: Sculpture

Subject Areas: Archaeological and Cultural Heritage, Materials, Chemistry


Instruments: I08-Scanning X-ray Microscopy beamline (SXM)

Added On: 08/01/2018 08:55

Documents:
1-s2.0-S1296207417305538-main.pdf

Discipline Tags:

Cultural Heritage Humanities Physical Chemistry Chemistry Corrosion Materials Science

Technical Tags:

Microscopy X-ray Microscopy Scanning X-ray Microscopy