title: Mechanoluminescence of SrAl2O4:Eu,Dy nanophosphors induced by low impact velocity.
abstract: The present paper reports the impulsive excitation of mechanoluminescence (ML) in Sr0.97Al2O4:Eu0.01,Dy0.02nanophosphors prepared using a combustion technique. The phosphors are characterized using X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL). The XRD results show that the samples exhibit a monoclinic α-phase in the crystal structure. The space group of SrAl2O4:Eu,Dy nanophosphors is monoclinic P21. The PL and ML spectra of SrAl2O4:Eu,Dy nanophosphors are excited using light with a wavelength of 365 nm and emission is found at 516 nm. The prepared nanophosphors exhibits an intense ML that can be seen in daylight with the naked eye. When a sample powder is deformed impulsively by the impact of a moving piston, the ML intensity initially increases linearly with time, attains a peak value, Im, at time tm, and then decreases with time. The peak ML intensity, Im, and total ML intensity, IT, increase linearly with applied pressure and impact velocity. The ML intensity decreases with successive impacts of load onto the phosphors, and the diminished ML intensity can be approximately recovered by UV irradiation. The activation energy using thermoluminescence is found to be 0.57 eV for SrAl2O4:Eu,Dy nanophosphors. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Applied Physics, Raipur Institute of Technology, Chhatauna, Mandir Hasuad, Raipur, 492101 (C.G.), India.
authors.forename: Piyush
authors.initials: P
authors.lastname: Jha
authors.affiliation: School of Studies in Physics and Astrophysics, Pt. Ravi Shankar Shukla University, Raipur, 492010 (C.G.), India.
authors.forename: B P
authors.initials: BP
authors.lastname: Chandra
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D004419:Dysprosium / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D049449:Luminescence; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D033362:Powder Diffraction; D013324:Strontium / Q000737:chemistry*
chemical_list: D004419:Dysprosium; D005063:Europium; D000535:Aluminum; D010100:Oxygen; D013324:Strontium
keywords: Sral2O4:Eu,Dy nanophosphors; mechanoluminescence; photoluminescence; thermoluminescence