Dynamic change in light-regulated hardness in SrTiO3

N Nant Nammahachak (Department of Tool and Materials Engineering, King Mongkut's University of Technology Thonburi 1 , 126 Pracha Uthit Rd., Thung Khru, Bangkok 10140,) M Manlika Sriondee T Tanachat Eknapakul (Functional Materials and Nanotechnology Center of Excellence, School of Science, Walailak University 4 , Nakhon Si Thammarat 80160,) A Arunothai Rattanachata (Synchrotron Light Research Institute 5 , Nakhon Ratchasima 30000,) H Hideki Nakajima (Synchrotron Light Research Institute (Public Organization) 111 University Avenue Muang District, Nakhon Ratchasima 30000 Thailand) J James P. Best (Max Planck Institute for Sustainable Materials 6 , Max-Planck-Straße 1, 40237 Düsseldorf,) W Worawat Meevasana N Narit Triamnak (Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University 8 , Nakhon Pathom 73000,) S Sutatch Ratanaphan (Department of Tool and Materials Engineering, King Mongkut's University of Technology Thonburi 1 , 126 Pracha Uthit Rd., Thung Khru, Bangkok 10140,)

Abstract

We report our discovery of the dynamic change in light-regulated hardness in an SrTiO3 single crystal. Vickers hardness and atomic force microscope measurements reveal that the hardness is surprisingly increased and decreased with on and off irradiation for a (110), but unchanged for a (100) oriented single crystal. The dynamic change of light-regulated hardness is primarily governed by a higher concentration of photo-induced oxygen vacancies in the (110) crystal compared to the (100), as revealed by photoelectron spectroscopy. This work provides an undiscovered route toward controlling the dynamic change of hardness, which may offer alternative strategies to tune the localized deformations in polycrystalline metal oxides.

Article Details

Volume / Issue Vol. 127, Issue 17
Published October 23, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (9)

N

Nant Nammahachak

Department of Tool and Materials Engineering, King Mongkut's University of Technology Thonburi 1 , 126 Pracha Uthit Rd., Thung Khru, Bangkok 10140,

M

Manlika Sriondee

T

Tanachat Eknapakul

Functional Materials and Nanotechnology Center of Excellence, School of Science, Walailak University 4 , Nakhon Si Thammarat 80160,

A

Arunothai Rattanachata

Synchrotron Light Research Institute 5 , Nakhon Ratchasima 30000,

H

Hideki Nakajima

Synchrotron Light Research Institute (Public Organization) 111 University Avenue Muang District, Nakhon Ratchasima 30000 Thailand

J

James P. Best

Max Planck Institute for Sustainable Materials 6 , Max-Planck-Straße 1, 40237 Düsseldorf,

W

Worawat Meevasana

N

Narit Triamnak

Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University 8 , Nakhon Pathom 73000,

S

Sutatch Ratanaphan

Department of Tool and Materials Engineering, King Mongkut's University of Technology Thonburi 1 , 126 Pracha Uthit Rd., Thung Khru, Bangkok 10140,