magnetic-materials-2018-posters-abstracts

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S e p t e m b e r 2 4 - 2 6 , 2 0 1 8 | B u d a p e s t , H u n g a r y

OF EXCELLENCE

IN INTERNATIONAL

MEETINGS

YEARS

Magnetic Materials 2018

Materials Science and Nanotechnology

Volume 2

MAGNETISM AND

MAGNETIC MATERIALS

International Conference on

Mater Sci Nanotechnol 2018, Volume 2

CORRELATION BETWEEN THE ELECTRONIC STRUCTURES AND

MAGNETIC PROPERTIES OF XE AND AR IONS IMPLANTED ZNO

Barun Ghosh

University of Nottingham, United Kingdom

strong correlation between the electronic structures andmagnetic properties of unimplanted ZnO single crystal (ZnO-SC) and

xenon (Xe

)/argon (Ar

) ions implanted ZnO SCs has been investigated using x-ray absorption near edge structure (XANES)

spectroscopy, valence band photoemission spectroscopy (VB-PES), x-ray photoelectron spectroscopy, ultraviolet photoelectron

spectroscopy, and a superconducting quantum interference device-type magnetometer. The XANES studies reveal the higher

number of unoccupied p-states in implanted ZnO SCs than pristine ZnO SCs. The enhancement in the absorption intensity of the

XANES spectra of implanted ZnO represents the enhanced local density of states (DOS) that arise from the surface defects or

dangling bonds in ZnO. In implanted ZnO SCs, the binding energy of the Zn 2p

3/2

core level peak shifts, which further confirms an

increase in the valence band maximum (VBM) position. The VB-PES spectra clearly change upon ions implantation, becoming

broader, implying the induced surface defects in ZnO-SC. VB-PES study also reveals that the number of electrons in the valence

band of the O 2p–Zn 4sp hybridized states of the implanted ZnO is higher than in the pristine ZnO. The magnetic M–H loops

demonstrate an enhanced room temperature ferromagnetism (RT-FM) in Xe/Ar ions implanted ZnO SCs, which is attributed to the

increasing number of surface defects and/or native defect sites such as oxygen vacancies and zinc interstitials. This increased

RT-FM is strongly related to the enhancement of VB-DOS of O 2p states close to Ef, because the population of defects and/or

vacancies at the O sites in irradiated ZnO is higher than pristine ZnO, which is confirmed from VB-PES as well as UPS studies.

This study confirms an enhanced room temperature ferromagnetism in Xe/Ar ions irradiated ZnO-SC without ant transition metal

doping which could be used in different electromagnetic applications.