摘要
铂族金属氮化物是一类新型超不可压缩超硬材料,通常借助激光加热金刚石压砧(laser-heated diamond anvil cell,LHDAC)技术,通过单质元素化合反应法(A+B=AB)在高温高压下(2 000 K、高于45 GPa)合成,探索有效降低合成压力的非常规化学合成方法对于开发和利用铂族金属(platinum-group metals,PGM)氮化物具有重要意义。以Fe_(2)O_(3)/Co_(2)O_(3)、h-BN、Os粉为反应前驱体,在大腔体压机提供的高温高压(1 800~2 100 K、15 GPa)条件下,首次通过新型高压偶联(high-pressure coupling,HPC)反应合成了OsN_(x)(0.16≤x≤0.38)。HPC反应合成出的金属块状产物一般为OsN_(x)与铁基氮化物复合的块体合金,利用微区X射线衍射、扫描电子显微镜对块状合金产物进行物相和结构表征,结果显示,HPC反应可以在远低于高压单质元素化合反应所需50 GPa压力阈值的条件下合成理论预测的六方OsN2结构的OsN_(x)(空间群为P63/mmc),N原子在Os晶体内部分占据晶格的间隙位。HPC反应能够有效降低金属Os氮化的能量势垒,形成非化学计量比的OsN_(x)化合物,为在低压条件下制备铂族金属氮化物块体材料开辟了一条新的合成途径。
Platinum-group metals(PGMs)nitrides represent a new class of super incompressible superhard materials,typically synthesized under extreme conditions(above 45 GPa,2000 K)using laser-heated diamond anvil cell(LHDAC)technology via monatomic elemental chemosynthesis(A+B=AB).Exploring non-conventional synthesis methods that significantly reduce the required pressures is crucial for advancing the development and application of PGMs nitrides.In this work,OsN_(x)(0.16≤x≤0.38)was synthesized for the first time via a novel high-pressure coupling(HPC)reaction,using Fe_(2)O_(3)/Co_(2)O_(3),h-BN,and Os powders as precursors under high-temperature and high-pressure conditions(15 GPa,1800-2100 K)in a large-volume press.The HPC-synthesized metal bulk products primarily consist of OsN_(x) alloyed with iron-based nitrides.Phase composition and structural characterization via X-ray powder diffraction(XRD)and scanning electron microscope(SEM)confirm the formation of hexagonal OsN_(2)(space group P63/mmc),as theoretically predicted,at pressures well below the 50 GPa threshold typically required for high-pressure monatomic elemental combination reactions.The nitrogen atoms partially occupy interstitial sites within the Os crystal structure.This study demonstrates that the HPC reaction effectively lowers the energy barrier for Os nitration,facilitating the formation of non-stoichiometric OsNx compounds.These findings open a new synthetic route for bulk PGM nitride materials under significantly reduced pressure conditions.
作者
刘德璞
张恒源
陶雨
贾旭
张瑞柯
贺端威
雷力
LIU Depu;ZHANG Hengyuan;TAO Yu;JIA Xu;ZHANG Ruike;HE Duanwei;LEI Li(Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,Sichuan,China)
出处
《高压物理学报》
北大核心
2025年第6期1-8,共8页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(U2030107)
中央高校基本科研业务费专项资金(2020SCUNL107)。
关键词
高压偶联反应
铂族金属氮化物
氮化锇
大腔体压机
高温高压
high-pressure coupling reaction
platinum-group metals nitrides
osmium nitrides
large-volume press
high-temperature and high-pressure
