Baek Chang Gyu, Rim Young Hoon, Ko Jae-Hyeon, Kim Chang-Seok, Yang Yong Suk
Department of Nanoenergy Engineering, College of Nanoscience and Nanotechnology, Pusan National University Busan 46241 South Korea
College of Liberal Arts, Semyung University Chungbuk 27136 South Korea
RSC Adv. 2020 Apr 7;10(24):14113-14121. doi: 10.1039/d0ra01541e. eCollection 2020 Apr 6.
We have investigated the transition kinetics of SrBaNbO (SBN) and LiBO (LBO) crystals from 0.25SrO-0.75BaO-NbO-LiO-2BO (SBNLBO) glass under isothermal and non-isothermal processes. With increasing temperature, there are two consecutive steps of crystallization of SBN and LBO from the glass. The Johnson-Mehl-Avrami function indicates that the crystallization mechanism of SBN belongs to an increasing nucleation rate with diffusion-controlled growth. The crystallite size of SBN ranges from 40 to 140 nm but it is confined to within 30-45 nm for LBO during the whole crystallization process. The relationship between the nano size and strain of SBN based on the Williamson-Hall method, and the change of activation energies of SBN and LBO crystallization analyzed by using the isoconversional model are discussed. A comparison of phonon modes between as-quenched glass and fully transformed crystals clearly shows that the low dimensional vibration modes in the structurally disordered glass change to highly dimensional network units with the formation of crystals.
我们研究了0.25SrO-0.75BaO-NbO-LiO-2BO（SBNLBO）玻璃在等温及非等温过程中SrBaNbO（SBN）和LiBO（LBO）晶体的转变动力学。随着温度升高，玻璃中SBN和LBO的结晶过程存在两个连续步骤。约翰逊-梅尔-阿夫拉米函数表明，SBN的结晶机制属于成核速率增加且生长受扩散控制。SBN的微晶尺寸范围为40至140纳米，但在整个结晶过程中，LBO的微晶尺寸限制在30至45纳米范围内。讨论了基于威廉姆森-霍尔方法的SBN纳米尺寸与应变之间的关系，以及利用等转化率模型分析的SBN和LBO结晶活化能的变化。对淬火玻璃和完全转变晶体的声子模式进行比较，结果清楚地表明，结构无序玻璃中的低维振动模式随着晶体形成转变为高维网络单元。
