Influence of ion irradiation on the surface electronic structure of epitaxial lanthanum nickelate films

Autor: Vishal Sharma, Inderpal Singh, null Sunidhi, Sunil K. Arora, Florencio Sánchez, Fouran Singh, Shilpa Tripathi, S.N. Jha
Přispěvatelé: European Commission, Panjab University, Ministerio de Ciencia, Innovación y Universidades (España)
Rok vydání: 2023
Předmět:
Zdroj: Surfaces and Interfaces
ISSN: 2468-0230
DOI: 10.1016/j.surfin.2023.102776
Popis: We studied the influence of Ag15+ (200 MeV) ion irradiation on the surface electronic structure of an epitaxial LaNiO3 films on a (100) oriented LaAlO3 substrate, using surface sensitive La (4d to 4f) and Ni (3p to 3d) photoemission transitions in the pristine, highest (1012 ions/cm2), medium (5 × 1011 ions/cm2), and lowest (1011 ions/cm2) ion-doses of irradiation. The Super-Coster Kronig induced slight enhancement in the spectral features around ∼115–116 eV photon energy for La (4d to 4f) transitions were observed, with absence of such enhancement for Ni (3p to 3d) transitions in the pristine and irradiated samples. Moreover, an alteration in the constant initial state (CIS) spectra for La (4d to 4f) transitions and presence of a surface states close to the Fermi level in the valence band spectra for Ni (3p to 3d) transitions, with a different ion-doses found to be associated with the oxygen vacancies. Interestingly for Ni (3p to 3d) transition spectra, the density of states (DOS) at the Fermi Level was found to increase orderly with the irradiation dose, and a systematic correlation between the DOS at Fermi level and the surface states was found in the pristine and irradiated samples. For the highest dose sample, the surface states lie above the Fermi level has highest DOS at the Fermi level, which is due to upward shift of the surface states towards the Fermi level with an increase in the irradiation dose.
This project has received funding from EU-H2020 research and innovation program under grant agreement No. 654360 within NFFA- Europe transnational access activity. We thanks Inter-University Accelerator center (IUAC), New Delhi, India, for providing access to ion- irradiation facility under duly approved projects IUAC/XIII.7/UFR-62333 and IUAC/XIII.3A/64207/MS (BTR-2). We also thanks Raja Ramanna center for Advanced Technology (RRCAT), Indore (India) for providing access to valence band spectroscopy measurements at INDUS-1. Vishal Sharma expresses his gratitude to Panjab University, Chandigarh (1019–40/Estt.-I dated 16/02/2017) and thereafter UGC-DAE CSR Indore (CSR-IC/BL-09/CRS-106/2019–20/202) for providing fellowship for carrying out research work. Ms. Sunidhi expresses her thanks to UGC, New Delhi for providing fellowship for research work. F. Sánchez acknowledges financial support from the Spanish Ministry of Science and Innovation, through the Severo Ochoa FUNFUTURE (CEX2019–000917-SMCIN AEI/10.13039/501100011033) and PID2020112548RB (MCIN/AEI/ 0.13039 /5011 000110 33).
With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).
Databáze: OpenAIRE
Externí odkaz: