CAJ | 학술논문

用XRD、Raman光谱和DSC研究了Al2 (MoO4)3、Cr2( MoO4)3和Fe2 (MoO4)3的结构与相变.Al2(MoO4)3、Cr2 (MoO4)3和Fe2 (MoO4)3在室温下为单斜相,分别在483 K、673 K和783 K附近转变为正交相.发现MO4四面体的对称和反对称伸缩振动模的频率和相对强度明显受到A3+离子的影响.这些模的软化程度受A3+离子的影响依次为Fe＞Cr＞A1,与A3+离子半径和电负性对MO4四面体的键强和灵活性的影响密切相关.
용XRD、Raman광보화DSC연구료Al2 (MoO4)3、Cr2( MoO4)3화Fe2 (MoO4)3적결구여상변.Al2(MoO4)3、Cr2 (MoO4)3화Fe2 (MoO4)3재실온하위단사상,분별재483 K、673 K화783 K부근전변위정교상.발현MO4사면체적대칭화반대칭신축진동모적빈솔화상대강도명현수도A3+리자적영향.저사모적연화정도수A3+리자적영향의차위Fe＞Cr＞A1,여A3+리자반경화전부성대MO4사면체적건강화령활성적영향밀절상관.
The structures and phase transition of Al2 (MoO4)3,Cr2 (MoO4)3 and Fe2 (MoO4)3 materials have been studied by XRD,Raman spectroscopy and DSC.It is shown that Al2 (MoO4)3,Cr2 (MoO4)3 and Fe2 (MoO4)3 crystallize in monoclinic structure at room temperature and transform to orthorhombic phase at about 483 K,673 K and 783 K,respectively.It is found that frequencies and relative intensities of the symmetric and asymmetric stretching vibrations of the MO4 tetraheda are obviously affected by A3+ cations.They exhibit obvious softening in the order of Fe3+＞ Cr3+＞ Al3+.This is attributed to the size and electronegativity effects of the A3+ cation on the bond strength and flexibility of the MO4 tetrahedra.