*** Memory effect in photochromic rare-earth oxyhydride thin films studied by in situ positron annihilation spectroscopy upon photodarkening-bleaching cycling *** 
Authors: Ziying Wu, Lidwin de Wit, Melanie Beek, Giorgio Colombi, Diana Chaykina, Herman Schreuders, Henk Schut, 
Maciej Oskar Liedke, Maik Butterling, Andreas Wagner, Marcel Dickmann, Ekkes Brück, Bernard Dam, and Stephan W. H. Eijt
TU Delft, Faculty of Applied Sciences, Department of Radiation Science and Technology
TU Delft, Faculty of Applied Sciences, Department of Chemical Engineering
Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics
Bundeswehr Universität München, Institut für angewandte Physik und Messtechnik
Corresponding author: Z.Wu 
Contact Information:
Z.Wu-2@tudelft.nl
Delft University of Technology, Faculty of Applied Sciences, Department of Radiation Science and Technology
Buildingnumber 50
Mekelweg 15
2629 JB Delft
The Netherlands
***General Introduction***
This dataset contains data collected during positron annihilation spectroscopy, transmittance, and X-ray diffraction experiments at Delft University 
of Technology, as part of Ziying Wu's PhD Thesis project (2024): 

It is being made public both to act as supplementary data for publications and the PhD 
thesis of Ziying Wu and in order for other researchers to use this data in their own 
work.
The data in this data set was collected in the Fundamental Aspects of Materials and Energy of the 
Delft University of Technology - Department of Radiation Science and Technology, between February 2020 
and August 2024.
This research project was financially supported by the Guangzhou Elite Project (GEP) and 
the Materials for Sustainability (Mat4Sus) research program, which is financed by the Netherlands Organization for Scientific Research (NWO).
***Purpose of this research and the key experimental methods used***
The purpose of these experiments was to investigate the microscopic mechanism of the memory effect in photochromic rare-earth oxyhydride 
thin films. In this study, positron annihilation spectroscopy, transmittance, and XRD were used, and the corresponding raw and processing data are included in this dataset.
***Description of the data in this data set***
The data in this dataset includes high-resolution figures, and corresponding raw and processing data. The raw and processing data for all 
measurements can be found under the file "raw data" and "processing data". 
The fits of DB-PAS depth profiles were obtained using VEPFIT, the positron lifetime spectra were fitted by PALSfit3.
