N. I. Solin, S. V. Naumov, A. V. Korolev, V. R. Galakhov
{"title":"Spin States of Cobalt Ions and a Metal–Semiconductor Transition in Layered Cobaltites PrBaCo2O5 + δ (δ = 0.52, 0.74)","authors":"N. I. Solin, S. V. Naumov, A. V. Korolev, V. R. Galakhov","doi":"10.1134/S1063776123110109","DOIUrl":null,"url":null,"abstract":"<p>The spin states of Co atoms in PrBaCo<sub>2</sub>O<sub>5 + δ</sub> with regard to the paramagnetic contribution of Pr<sup>3+</sup> ions have been determined from magnetic property studies for δ = 0.52 and 0.74. Results obtained without considering the paramagnetic contribution of Pr<sup>3+</sup> ions are inconsistent with available experimental data. With a decrease in temperature, the metal–insulator transition in PrBaCo<sub>2</sub>O<sub>5.52</sub> becomes sharper according to a sharp change in spin states (from HS/LS to LS/IS) of Co<sup>3+</sup> ions. In this case, Co<sup>3+</sup> ions occupying octahedra pass from the high-spin state (HS, <i>S</i> = 2) to the low-spin one (LS, <i>S</i> = 0) and those occupying pyramids pass from the LS-state to the intermediate spin state (IS, <i>S</i> = 1), as follows from the available structural data. In PrBaCo<sub>2</sub>O<sub>5.74</sub>, the metal–semiconductor transition occurs smoothly from HS/LS to the HS/IS state upon the smooth transition of the Co<sup>3+</sup> ion state from (LS, <i>S</i> = 0) to the (IS, <i>S</i> = 1) state in pyramides without change in the spin state of ions Co<sup>3+</sup> (HS, <i>S</i> = 2) and Co<sup>4+</sup> (LS, <i>S</i> = 1/2) in octahedrons.</p>","PeriodicalId":629,"journal":{"name":"Journal of Experimental and Theoretical Physics","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Experimental and Theoretical Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1134/S1063776123110109","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The spin states of Co atoms in PrBaCo2O5 + δ with regard to the paramagnetic contribution of Pr3+ ions have been determined from magnetic property studies for δ = 0.52 and 0.74. Results obtained without considering the paramagnetic contribution of Pr3+ ions are inconsistent with available experimental data. With a decrease in temperature, the metal–insulator transition in PrBaCo2O5.52 becomes sharper according to a sharp change in spin states (from HS/LS to LS/IS) of Co3+ ions. In this case, Co3+ ions occupying octahedra pass from the high-spin state (HS, S = 2) to the low-spin one (LS, S = 0) and those occupying pyramids pass from the LS-state to the intermediate spin state (IS, S = 1), as follows from the available structural data. In PrBaCo2O5.74, the metal–semiconductor transition occurs smoothly from HS/LS to the HS/IS state upon the smooth transition of the Co3+ ion state from (LS, S = 0) to the (IS, S = 1) state in pyramides without change in the spin state of ions Co3+ (HS, S = 2) and Co4+ (LS, S = 1/2) in octahedrons.
期刊介绍:
Journal of Experimental and Theoretical Physics is one of the most influential physics research journals. Originally based on Russia, this international journal now welcomes manuscripts from all countries in the English or Russian language. It publishes original papers on fundamental theoretical and experimental research in all fields of physics: from solids and liquids to elementary particles and astrophysics.