Exploration of novel multinary nitrides containing alkaline-earth metal elements by the sodium flux method

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420701
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic materials/Physical properties
• Research Institution: Tohoku University
• Principal Investigator: Yamane Hisanori 東北大学, 多元物質科学研究所, 教授 (20191364)
• Co-Investigator(Renkei-kenkyūsha): MORITO Haruhiko 東北大学, 多元物質科学研究所, 助教 (80463800)
• Research Collaborator: YAMADA Takahiro 東北大学, 多元物質科学研究所, 准教授 (10358260) ; HASHIMOTO Takayuki 東北大学, 多元物質科学研究所, 修士学生 ; Becker Nils アーヘン工科大学, 博士学生 ; Dronskowski Richard アーヘン工科大学, 教授
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 窒化物 / 酸窒化物 / ナトリウムフラックス / ジントルポリアニオン / ジントル化合物 / 結晶構造 / 化学結合

Outline of Final Research Achievements

Novel compounds, Ba4GaN3O, BaLaSi2, Ba5LaSi6, and Ba26B12Si5N27 were synthesized by the Na flux method. The crystal structure of Ba4GaN3O is isotypic with Sr4GaN3O. BaLaSi2 has cis-trans ∞1[Si] chains. 0[Si6] Zintl polyanion　in Ba5LaSi6 is a pentagonal Si ring with a Si-Si stem. The electrical resistivities of BaLaSi2 and Ba5LaSi6 were 0.31 and 0.48 mΩ・cm at 300 K and increased with temperature. The Seebeck coefficients of BaLaSi2 and Ba5LaSi6 were -7.6 μV・K-1 and -11 μV・K-1, respectively, at 296 K. Single crystals of a new quaternary compound, Ba26B12Si5N27, were grown on a BN crucible wall. X-ray diffraction analysis revealed that Ba26B12Si5N27 crystallizes in an orthorhombic cell. Isolated nitridoborate anionic groups [BN2]3-;, dumbbell-type Zintl polyanions [Si2]2.8-, and nitride anions N3- are included in the structure. The [Si2]2.8- dumbbell with a Si-Si length of 2.177(5) Å has a bond order of 2.6, which is close to the triple bond of Si atoms.

Free Research Field

無機固体化学、無機結晶化学