Victoria Kyveryga, Philip Yox, Gayatri Viswanathan, Arka Sarkar, Lin-Lin Wang, Kirill Kovnir
{"title":"BaAg2-xAs2 中银空位的成因、后果和控制。","authors":"Victoria Kyveryga, Philip Yox, Gayatri Viswanathan, Arka Sarkar, Lin-Lin Wang, Kirill Kovnir","doi":"10.1021/acs.inorgchem.4c03006","DOIUrl":null,"url":null,"abstract":"<p><p>The impact of transition metal (Ag) deficiencies on the structural and transport properties of ThCr<sub>2</sub>Si<sub>2</sub>-type arsenides are investigated. We experimentally confirm a partial occupancy of Ag in BaAg<sub>2-<i>x</i></sub>As<sub>2</sub>, which can be predictably controlled within 0.053(5) ≤ <i>x</i> ≤ 0.19(1) by varying the quenching temperature during the crystal growth. Density functional theory calculations reveal that substoichiometric concentrations of Ag lower the density of states at the Fermi level, providing an electronic cause for the tendency of Ag to form vacancies. This vacancy concentration is linked to a characteristic kink in electrical resistivity that can be substantially shifted from 22 to 125 K and is established as the metric of a low-temperature structural phase transition (SPT) in BaAg<sub>2-<i>x</i></sub>As<sub>2</sub>. Along with electrical resistivity, the Seebeck coefficient and heat capacity for selected BaAg<sub>2-<i>x</i></sub>As<sub>2</sub> samples are presented, which also exhibit anomalies due to the SPT.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Cause, Consequence, and Control of Ag Vacancies in BaAg<sub>2-<i>x</i></sub>As<sub>2</sub>.\",\"authors\":\"Victoria Kyveryga, Philip Yox, Gayatri Viswanathan, Arka Sarkar, Lin-Lin Wang, Kirill Kovnir\",\"doi\":\"10.1021/acs.inorgchem.4c03006\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The impact of transition metal (Ag) deficiencies on the structural and transport properties of ThCr<sub>2</sub>Si<sub>2</sub>-type arsenides are investigated. We experimentally confirm a partial occupancy of Ag in BaAg<sub>2-<i>x</i></sub>As<sub>2</sub>, which can be predictably controlled within 0.053(5) ≤ <i>x</i> ≤ 0.19(1) by varying the quenching temperature during the crystal growth. Density functional theory calculations reveal that substoichiometric concentrations of Ag lower the density of states at the Fermi level, providing an electronic cause for the tendency of Ag to form vacancies. This vacancy concentration is linked to a characteristic kink in electrical resistivity that can be substantially shifted from 22 to 125 K and is established as the metric of a low-temperature structural phase transition (SPT) in BaAg<sub>2-<i>x</i></sub>As<sub>2</sub>. Along with electrical resistivity, the Seebeck coefficient and heat capacity for selected BaAg<sub>2-<i>x</i></sub>As<sub>2</sub> samples are presented, which also exhibit anomalies due to the SPT.</p>\",\"PeriodicalId\":40,\"journal\":{\"name\":\"Inorganic Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.3000,\"publicationDate\":\"2024-10-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Inorganic Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1021/acs.inorgchem.4c03006\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganic Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.inorgchem.4c03006","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Cause, Consequence, and Control of Ag Vacancies in BaAg2-xAs2.
The impact of transition metal (Ag) deficiencies on the structural and transport properties of ThCr2Si2-type arsenides are investigated. We experimentally confirm a partial occupancy of Ag in BaAg2-xAs2, which can be predictably controlled within 0.053(5) ≤ x ≤ 0.19(1) by varying the quenching temperature during the crystal growth. Density functional theory calculations reveal that substoichiometric concentrations of Ag lower the density of states at the Fermi level, providing an electronic cause for the tendency of Ag to form vacancies. This vacancy concentration is linked to a characteristic kink in electrical resistivity that can be substantially shifted from 22 to 125 K and is established as the metric of a low-temperature structural phase transition (SPT) in BaAg2-xAs2. Along with electrical resistivity, the Seebeck coefficient and heat capacity for selected BaAg2-xAs2 samples are presented, which also exhibit anomalies due to the SPT.
期刊介绍:
Inorganic Chemistry publishes fundamental studies in all phases of inorganic chemistry. Coverage includes experimental and theoretical reports on quantitative studies of structure and thermodynamics, kinetics, mechanisms of inorganic reactions, bioinorganic chemistry, and relevant aspects of organometallic chemistry, solid-state phenomena, and chemical bonding theory. Emphasis is placed on the synthesis, structure, thermodynamics, reactivity, spectroscopy, and bonding properties of significant new and known compounds.