Abstract

NiFe₂O₄ nanoparticles were synthesized by HMTA-assisted hydrothermal method, annealed at 600, 800, and 1000°C for 4 h, and characterized by XRD and high-resolution SEM. As the Debye–Scherer formula gives only rough estimation for crystallite size D and micro strain ε, so we used Williamson–Hall (WH) plot and size–strain (SS) plot methods to study relative contribution from crystallite size and lattice strain to crystal structure of synthesized ferrites. The values of D and ε were evaluated in terms of several models based on the Debye–Scherer formula (SM), modified Scherer formula (MSM), WH plot method (WHM), and SS plot method (SSM). It has been found that the size–strain method gives best fit and is most suitable for estimations of crystallite size. The WHM and SSM results are indicative of the occurrence of compressive strain in all studied crystals. Crystallite size was found to increase while micro strain, to decrease with increasing annealing temperature.

中文翻译：

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根据各种模型计算得出的NiFe 2 O 4纳米颗粒中的微晶尺寸和压缩晶格应变：退火温度的影响

摘要

采用HMTA辅助水热法合成NiFe ₂ O ₄纳米粒子，在600、800和1000℃下退火4 h，并通过XRD和高分辨率SEM进行表征。由于Debye-Scherer公式仅给出了晶粒尺寸D和微应变ε的粗略估计，因此我们使用Williamson-Hall（WH）图和尺寸-应变（SS）图方法研究了晶粒尺寸和晶格应变对晶体的相对贡献合成铁氧体的结构。D的值根据Debye-Scherer公式（SM），改进的Scherer公式（MSM），WH绘图法（WHM）和SS绘图法（SSM），根据几种模型对ε和ε进行了评估。已经发现，尺寸-应变方法最适合并且最适合于微晶尺寸的估计。WHM和SSM结果表明在所有研究的晶体中都出现了压缩应变。发现微晶尺寸增加而微应变则随着退火温度的升高而减小。