采用顶部籽晶法生长了La3+掺杂Pb(Lu1/2Nb1/2)O3(PLN)反铁电单晶, 晶体组分简写为xLa-PLN(x=1%、3%、5%), 并详细研究了La3+掺杂对PLN晶体储能性能的影响。通过ICP测试了不同配比晶体的实际掺杂比例, 分别为0.3%、1.1%、2.9%。XRD显示该晶体体系为正交相钙钛矿结构, 且存在两套超晶格衍射点阵, 分别由A位铅离子反平行排列和B位离子有序排列导致。介电温谱给出了晶体的介电常数、介电损耗随温度和频率的变化规律, 不存在弥散相变。变温电滞回线显示, 该体系均表现出典型的双电滞回线特性, 且随着La3+含量的增加, 有效储能密度逐渐增大, 最高储能密度达到5.1 J/cm3。这主要是由于La3+掺杂导致体系的容忍因子下降, 从而增强了反铁电稳定性, 最终提高了PLN体系的能量存储密度。

Effect of La3+-doping on energy storage performance of Pb(Lu1/2Nb1/2)O3 antiferroelectric(AFE) single crystals (abbreviated as xLa-PLN, x=1%, 3%, 5%) was studied, which is abtained by the top-seed growth method. The actual components of these crystals were 0.3%, 1.1% and 2.9% by ICP test, respectively. The crystal structure is found to be perovskite orthorhombic in nature based on the XRD analysis. In addition, two superlattice reflections are identified, which stem from the antiparallel displacements of the Pb2+ and the ordered B-site ions. The dielectric spectrum shows the variation of dielectric constant, dielectric loss as a function of temperature and frequencies, and there is no diffuse phase transition. This system shows the typical double hysteresis loops and the energy storage density gradually increases with increasing La3+ content, which can reach to 5.1 J/cm3. This is mainly because La3+-doping leads to a decrease in the tolerance factor, which enhances the stability of antiferroelectric, eventually increasing the energy density of this system.