NMR study of defect-induced magnetism in methylammonium lead iodide perovskite
| Autor: | Bilwadal Bandyopadhyay, Joydeep Dhar, Palash Nath, Dirtha Sanyal, Mahuya Chakrabarti, Homnath Luitel, Partha Pratim Ray, Sayantan Sil |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Condensed matter physics Magnetic moment Magnetism Order (ring theory) 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences NMR spectra database Condensed Matter::Materials Science Magnetization Paramagnetism Ferromagnetism 0103 physical sciences Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Perovskite (structure) |
| Zdroj: | Physical Review B. 101 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | In organic-inorganic perovskite semiconductor methylammonium lead iodide the occurrence of magnetism has been confirmed from magnetization and $^{1}\mathrm{H}$ nuclear magnetic resonance (NMR) measurements. From room temperature down to 4 K, the magnetization is a combination of weak ferromagnetism and paramagnetism. $^{1}\mathrm{H}$ NMR spectra at low temperatures also reveal two components, one with a small chemical shift characteristic of $^{1}\mathrm{H}$ resonance in nonmetals, and the other with a much larger shift of $\ensuremath{\sim}\ensuremath{-}100$ ppm that is ascribed to the ferromagnetism of the material. The analysis of NMR spectra as well as that of $^{1}\mathrm{H}$ spin-lattice relaxation rate ($1/{T}_{1}$) indicates that disorder produces an inhomogeneous distribution of magnetic moments that order ferromagnetically where they are dense enough and otherwise behave as random paramagnetic impurities. It is shown that magnetism arises from iodine and lead vacancies present in the orthorhombic and cubic crystal phases of the material. |
| Databáze: | OpenAIRE |
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