High-pressure X-ray diffraction and Raman spectroscopy of Ca2AlFeO5 brownmillerite
High-pressure X-ray diffraction and Raman spectroscopy of Ca2AlFeO5 brownmillerite
复制标题
Ca2AlFeO5 褐针石的高压 X 射线衍射和拉曼光谱
DOI：
10.1080/08957959.2019.1571587
复制
发表时间：
--
影响因子：
2
通讯作者：
Shuangmeng Zhai
中科院分区：
文献类型：
--
作者：
Zeming Li;Yuan Yin;Justin D. Rumney;Sean R. Shieh;Jingui Xu;Dawei Fan;Wen Liang;Shuai Yan;Shuangmeng Zhai
采用原位同步x射线衍射和拉曼光谱研究了Ca2AlFeO5brownmillerite在300 K、26.5和32.1 GPa压力下的行为。观察到可逆的结构相变。p - v数据采用三阶Birch-Murnaghan状态方程进行拟合，得到等温体积模量为k0 = 181.9(76) GPa, k0′= 4.4（17）。将k0′固定为4，得到k0为183.8(20)GPa。Ca2AlFeO5brownmillerite表现出轴向弹性各向异性，因为b轴比c轴更可压缩。结合前人的研究结果，Ca2AlFeO5brownmillerite的等温体积模量和轴向压缩率随着Al含量的增加而增加。分析了Ca2AlFeO5brownmillerite的拉曼光谱，压力系数在2.23 ~ 4.90 cm−1/GPa之间。等温模式grisen参数范围为0.83 ~ 1.77，热grisen参数确定为1.08（11）。
The behavior of Ca2AlFeO5brownmillerite was studied byin situsynchrotron X-ray diffraction and Raman spectroscopy at 300 K with pressures up to 26.5 and 32.1 GPa, respectively. A reversible structural phase transition was observed. TheP–Vdata were fitted by a third-order Birch–Murnaghan equation of state, and the isothermal bulk modulus was obtained asK0= 181.9(76) GPa withK0′= 4.4(17). IfK0′ was fixed to 4,K0was obtained as 183.8(20) GPa. Ca2AlFeO5brownmillerite shows an axial elastic anisotropy since theb-axis is more compressible thana-andc-axis. Combined with previous results, the isothermal bulk modulus and axial compressibility of Ca2AlFeO5brownmillerite increase with more Al incorporated in the structure. The Raman spectra of Ca2AlFeO5brownmillerite were analyzed and the pressure coefficients vary from 2.23 to 4.90 cm−1/GPa. The isothermal mode Grüneisen parameters range from 0.83 to 1.77 and the thermal Grüneisen parameter is determined as 1.08(11).