複雜性氧化物由於在電荷、自旋、晶體間的強關聯作用而展現出多樣的物理性質，例如釔鋇銅氧化物(YBa2Cu3O7)的超導性質、鉛鈦氧化物(PbTiO3)的鐵電效應、鑭鈣錳氧化物((La,Ca)MnO3)的龐磁阻效應以及本次研究的材料-鍶釕氧化物(SrRuO3)的光致伸縮效應。
之前有研究利用光致伸縮效應去操控SrRuO3的晶格常數進而達到操控其拉曼Ag振動模態的效果[1]，然而，有關晶體應變對拉曼模的影響資訊尚有不足之處，因此在本次研究中我們利用第一原理去探討SrRuO3的拉曼振動模態在應變下的行為，並以原子受彈性力的角度出發去探討其聲子行為的成因。

本次的研究分成三大部分:
第一部分利用第一原理計算SrRuO3拉曼聲子在無應變下的頻率及振動模式，並以原子間受彈性力的觀點去探討聲子頻率大小及振動模式間的關聯。
第二部分利用第一原理計算分別對SrRuO3之a,b,c軸分別施加應變並計算其頻率飄移，再以原子彈性力去探討聲子頻率飄移和原子漂移、振動模式的關聯。
第三部分利用第一原理計算對SrRuO3施加多軸應變(有別於上一部分的單軸應變)並計算其頻率飄移，再以原子彈性力去探討和歸納聲子在多軸應變及單軸應變下行為的關聯。

Strontium ruthenate (SrRuO3) is a perovskite crystal structure with Pnma symmetry. The characteristics of the strong coupling among charge, spin, orbital, and lattice degrees of freedom give rise to various physical properties. The recent study shows that the light-induced Raman shifts of SRO due to the photostriction effect indicate the change of the strained state. However, the information about the relation of strained states to the Raman modes is still less; therefore, in this research, we use the elastic force theory and first-principle calculation to study the SrRuO3 phonon behaviors under strains. We separate our study into two parts. In the first part,we obtain the phonon under no strain by using first-principle calculation. In the second part, to obtain the phonon behaviors in different strained states, the stress is applied along the a, b, c axis of the SrRuO3 orthorhombic cell, respectively. In the end of both part above, under the concept of the interaction among atoms, we use the elastic theory to explain the phonon behaviors in different strained states.

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