论文标题
铁电纳米颗粒大小的分布函数对其电源和pyroelectric特性的影响
The influence of the distribution function of ferroelectric nanoparticles sizes on their electrocaloric and pyroelectric properties
论文作者
论文摘要
我们考虑基于嵌入介电基质中各种尺寸的非相互作用球形单域纳米颗粒的纳米复合材料模型。这些纳米颗粒的尺寸分布函数被选择为从最小半径到最大半径的高斯分布的一部分(截断的正态分布)。对于此类纳米复合材料,我们计算了电动极化的可逆部分,电位温度变化以及对外部电场的介电介电常数的依赖性,这些电场具有磁滞环的特征形式。然后,我们分析相对于粒度分布参数的磁滞回路形状的变化。我们证明,对于相同的均方分子分散,不遗物极化,强制性场,介电介电常数的最大值,最大和最小值的电核温度变化最大程度最大取决于最可能的半径,中度取决于分散体,并且对Nananoparpiles的最大依赖性最大依赖性。我们计算并分析了绩效上的高电数字对复合材料中纳米颗粒平均半径的依赖性。依赖性证实了由纳米颗粒的大小引起的相变的存在,其特征在于粒子临界平均半径附近的最大值,其值随着分布函数的分散体的增加而增加。
We consider a model of a nanocomposite based on non-interacting spherical single-domain ferroelectric nanoparticles of various sizes embedded in a dielectric matrix. The size distribution function of these nanoparticles is selected as a part of the Gaussian distribution from minimum to maximum radius (truncated normal distribution). For such nanocomposites, we calculate the dependences of the reversible part of the electric polarization, the electrocaloric temperature change, and the dielectric permittivity on the external electric field, which have the characteristic form of hysteresis loops. We then analyze the change in the shape of the hysteresis loops relative to the particle size distribution parameters. We demonstrate that for the same mean-square dispersion, the remanent polarization, coercive field, dielectric permittivity maximums, maximums and minimums of the electrocaloric temperature change depend most strongly on the most probable radius, moderately depend on the dispersion, and have the weakest dependency on the nanoparticle maximum radius. We calculated and analyzed the dependences of pyroelectric figures of merit on the average radius of the nanoparticles in the composite. The dependences confirm the presence of a phase transition induced by the size of the nanoparticles, which is characterized by the presence of a maxima near the critical average radius of the particles, the value of which increases with increasing dispersion of the distribution function.