Margarida Barroso, Mian Dai, Cora Bubeck, Marco Scavini, Gabriel J. Cuello, Hongbin Zhang, Anke Weidenkaff, Marc Widenmeyer
{"title":"Investigation of O/N Ordering in Perovskite-Type Oxynitrides La1−xYxTa(O,N)3 on Long Range and Short Scale","authors":"Margarida Barroso, Mian Dai, Cora Bubeck, Marco Scavini, Gabriel J. Cuello, Hongbin Zhang, Anke Weidenkaff, Marc Widenmeyer","doi":"10.3390/inorganics12030090","DOIUrl":null,"url":null,"abstract":"Oxynitrides such as LaTa(O,N)3 are attractive materials as photoelectrodes for photoelectrocatalytic solar water splitting. The potential anionic ordering in their perovskite-type structure has been shown to impact the materials’ properties. Given the importance attributed to it, the present study reports a detailed experimental analysis supported by simulations of the anionic ordering of La1−xYxTa(O,N)3. The influence of O/N and yttrium content on the anionic order was assessed. Neutron diffraction analysis was performed on four different nominal compositions—LaTaON2, LaTaO2N, La0.9Y0.1TaON2, and La0.9Y0.1TaO2N—at 10 K and 300 K to study potential long-range ordering. Neutron pair distribution function (PDF) analysis was performed on all samples at 10 K and on non-Y-substituted samples at 300 K to evaluate short-range ordering. There was no evidence of long-range O/N order in any of the compounds. In contrast, at a short range (1.5 Å ≤ r < 6 Å), a Pnma (a−b+a−) tilting pattern and local cis-ordering of the anions were seen. The latter faded rapidly, leaving the Pnma tilting pattern in a 6 Å ≤ r ≤ 11 Å range. At higher distances, the PDF analysis agreed with the Imma (a−b0a−) O/N disordered long-range structure. As the O/N content changed, not much difference in behavior was observed. Yttrium substitution introduced some disorder in the structure; nonetheless, it showed marginal influence on octahedral tilting and anionic ordering.","PeriodicalId":507601,"journal":{"name":"Inorganics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/inorganics12030090","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Oxynitrides such as LaTa(O,N)3 are attractive materials as photoelectrodes for photoelectrocatalytic solar water splitting. The potential anionic ordering in their perovskite-type structure has been shown to impact the materials’ properties. Given the importance attributed to it, the present study reports a detailed experimental analysis supported by simulations of the anionic ordering of La1−xYxTa(O,N)3. The influence of O/N and yttrium content on the anionic order was assessed. Neutron diffraction analysis was performed on four different nominal compositions—LaTaON2, LaTaO2N, La0.9Y0.1TaON2, and La0.9Y0.1TaO2N—at 10 K and 300 K to study potential long-range ordering. Neutron pair distribution function (PDF) analysis was performed on all samples at 10 K and on non-Y-substituted samples at 300 K to evaluate short-range ordering. There was no evidence of long-range O/N order in any of the compounds. In contrast, at a short range (1.5 Å ≤ r < 6 Å), a Pnma (a−b+a−) tilting pattern and local cis-ordering of the anions were seen. The latter faded rapidly, leaving the Pnma tilting pattern in a 6 Å ≤ r ≤ 11 Å range. At higher distances, the PDF analysis agreed with the Imma (a−b0a−) O/N disordered long-range structure. As the O/N content changed, not much difference in behavior was observed. Yttrium substitution introduced some disorder in the structure; nonetheless, it showed marginal influence on octahedral tilting and anionic ordering.
氮氧化物(如 LaTa(O,N)3)作为光电催化太阳能水分离的光电极是一种极具吸引力的材料。其包晶型结构中潜在的阴离子有序性已被证明会影响材料的特性。鉴于其重要性,本研究报告对 La1-xYxTa(O,N)3 的阴离子有序性进行了详细的实验分析,并辅以模拟,评估了 O/N 和钇含量对阴离子有序性的影响。在 10 K 和 300 K 下,对四种不同的标称成分--LaTaON2、LaTaO2N、La0.9Y0.1TaON2 和 La0.9Y0.1TaO2N 进行了中子衍射分析,以研究潜在的长程有序性。在 10 K 时对所有样品进行了中子对分布函数 (PDF) 分析,在 300 K 时对非 Y 取代样品进行了中子对分布函数 (PDF) 分析,以评估短程有序性。没有证据表明任何化合物存在长程 O/N 排序。相反,在短程(1.5 Å ≤ r < 6 Å)范围内,出现了 Pnma (a-b+a-) 倾斜模式和阴离子的局部顺式排序。后者迅速消失,留下了 6 Å ≤ r ≤ 11 Å 范围内的 Pnma 倾斜模式。在更高的距离上,PDF 分析与 Imma (a-b0a-) O/N 无序长程结构一致。随着 O/N 含量的变化,观察到的行为差异不大。钇的替代在结构上引入了一些无序;然而,它对八面体倾斜和阴离子有序的影响微乎其微。