Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate
We studied the structural transformations and atomic rearrangements in strontium titanate (SrTiO<sub>3</sub>) via nanosecond pulsed laser irradiation-induced melting and ultrafast quenching. Using scanning transmission electron microscopy, we determine that the laser-irradiated surface i...
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MDPI AG
2022-04-01
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| Online Access: | https://www.mdpi.com/2073-4352/12/5/624 |
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| author | Ashish Kumar Gupta Siddharth Gupta Soumya Mandal Ritesh Sachan |
| author_facet | Ashish Kumar Gupta Siddharth Gupta Soumya Mandal Ritesh Sachan |
| author_sort | Ashish Kumar Gupta |
| collection | DOAJ |
| description | We studied the structural transformations and atomic rearrangements in strontium titanate (SrTiO<sub>3</sub>) via nanosecond pulsed laser irradiation-induced melting and ultrafast quenching. Using scanning transmission electron microscopy, we determine that the laser-irradiated surface in single-crystalline SrTiO<sub>3</sub> transforms into an amorphous phase with an interposing disordered crystalline region between amorphous and ordered phases. The formation of disordered phase is attributed to the rapid recrystallization of SrTiO<sub>3</sub> from the melt phase constrained by an epitaxial relation with the pristine region, which eases up on the surface, leading to amorphous phase formation. With electron energy-loss spectroscopic analysis, we confirm the transformation of Ti<sup>+4</sup> to Ti<sup>+3</sup> due to oxygen vacancy formation as a result of laser irradiation. In the disordered region, the maximum transformation of Ti<sup>+4</sup> is observed to be 16.2 ± 0.2%, whereas it is observed to be 20.2 ± 0.2% in the amorphous region. Finally, we deduce that the degree of the disorder increases from atomically disordered to amorphous transition in SrTiO<sub>3</sub> under laser-irradiation. The signatures of short-range ordering remain similar, leading to a comparable fingerprint of electronic structure. With these results, this study addresses the gap in understanding the atomic and electronic structure modified by pulsed laser irradiation and functionalizing pristine SrTiO<sub>3</sub> for electronic, magnetic, and optical applications. |
| first_indexed | 2024-03-10T03:04:54Z |
| format | Article |
| id | doaj.art-7ead753f7ae2446da8387ba5723ff40e |
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| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-10T03:04:54Z |
| publishDate | 2022-04-01 |
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| record_format | Article |
| series | Crystals |
| spelling | doaj.art-7ead753f7ae2446da8387ba5723ff40e2023-11-23T10:34:35ZengMDPI AGCrystals2073-43522022-04-0112562410.3390/cryst12050624Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium TitanateAshish Kumar Gupta0Siddharth Gupta1Soumya Mandal2Ritesh Sachan3School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, USAMaterials Science and Engineering, North Carolina State University, Raleigh, NC 27606, USASchool of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, USASchool of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, USAWe studied the structural transformations and atomic rearrangements in strontium titanate (SrTiO<sub>3</sub>) via nanosecond pulsed laser irradiation-induced melting and ultrafast quenching. Using scanning transmission electron microscopy, we determine that the laser-irradiated surface in single-crystalline SrTiO<sub>3</sub> transforms into an amorphous phase with an interposing disordered crystalline region between amorphous and ordered phases. The formation of disordered phase is attributed to the rapid recrystallization of SrTiO<sub>3</sub> from the melt phase constrained by an epitaxial relation with the pristine region, which eases up on the surface, leading to amorphous phase formation. With electron energy-loss spectroscopic analysis, we confirm the transformation of Ti<sup>+4</sup> to Ti<sup>+3</sup> due to oxygen vacancy formation as a result of laser irradiation. In the disordered region, the maximum transformation of Ti<sup>+4</sup> is observed to be 16.2 ± 0.2%, whereas it is observed to be 20.2 ± 0.2% in the amorphous region. Finally, we deduce that the degree of the disorder increases from atomically disordered to amorphous transition in SrTiO<sub>3</sub> under laser-irradiation. The signatures of short-range ordering remain similar, leading to a comparable fingerprint of electronic structure. With these results, this study addresses the gap in understanding the atomic and electronic structure modified by pulsed laser irradiation and functionalizing pristine SrTiO<sub>3</sub> for electronic, magnetic, and optical applications.https://www.mdpi.com/2073-4352/12/5/624pulsed laser irradiationstrontium titanatehigh-angle annular dark-field imagingelectron energy-loss spectroscopyoxygen vacancies |
| spellingShingle | Ashish Kumar Gupta Siddharth Gupta Soumya Mandal Ritesh Sachan Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate Crystals pulsed laser irradiation strontium titanate high-angle annular dark-field imaging electron energy-loss spectroscopy oxygen vacancies |
| title | Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate |
| title_full | Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate |
| title_fullStr | Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate |
| title_full_unstemmed | Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate |
| title_short | Laser Irradiation-Induced Nanoscale Surface Transformations in Strontium Titanate |
| title_sort | laser irradiation induced nanoscale surface transformations in strontium titanate |
| topic | pulsed laser irradiation strontium titanate high-angle annular dark-field imaging electron energy-loss spectroscopy oxygen vacancies |
| url | https://www.mdpi.com/2073-4352/12/5/624 |
| work_keys_str_mv | AT ashishkumargupta laserirradiationinducednanoscalesurfacetransformationsinstrontiumtitanate AT siddharthgupta laserirradiationinducednanoscalesurfacetransformationsinstrontiumtitanate AT soumyamandal laserirradiationinducednanoscalesurfacetransformationsinstrontiumtitanate AT riteshsachan laserirradiationinducednanoscalesurfacetransformationsinstrontiumtitanate |