Growth And Properties Of Re:ErFeO₃ Crystals

Recently,due to the discovery of laser-induced ultrafast spin reorientation,multi-ferro and low-temperature strong magnetoelectric coupling effects in the orthorhombic perovskite structure rare earth Orthoferrite RFeO3,this material has attracted widespread attention in the field of condensed matter research and has become the focus of this research.However,because of the high melting point of RFeO₃ crystal and other factors,the problem of low quality of RFeO₃ single crystal has always existed,which has a negative impact on its further application.The performance of perovskite can be adjusted through proper doping,which is also a research hotspot in this area.In this thesis,ErFeO₃,Gd_0.4Er_0.6FeO₃ and Dy_0.4Er_0.6FeO₃ crystals are selected as research objects.Single-crystals are grown by optical floating zone method using high-purity oxide powders as raw materials.The preparation process,multi-iron performance and magnetic properties Can start research.Through a large number of crystal growth experiments,the process conditions for stable growth were determined,and high quality single crystals were obtained.The quality of the single crystal was analyzed by the phase structure,and the wafers in three directions of a,b,and c were obtained by directional cutting.The multiferroicity test of ErFeO₃,Gd_0.4Er_0.6FeO₃ and Dy_0.4Er_0.6FeO₃ crystals,the dielectric constant decreases with the doping of rare earth ions and decreases with increasing frequency.The crystal exhibits antiferromagnetic transition characteristics at high temperature,and the transition temperature moves to the high temperature region with increasing frequency.Gd-doped crystals exhibit iron electrodeposition at room temperature.For the magnetic test of the crystal,the hysteresis loop shows the antiferromagnetism of the sample,and it also shows weak ferromagnetism due to the D-M interaction.The magnetic temperature curve shows that Dy_0.4Er_0.6FeO₃ crystals above 60K Fe³⁺are antiferromagnetic coupling in the a and c directions,weak ferromagnetism occurs in the b direction.In addition,the magnetic temperature curves under different magnetic fields show that the magnetization increases with the increase of the magnetic field.When the magnetic field increases to 4T,the total magnetic moment in the a direction increases to 85 emu/g,and the differences in the a and b directions under high magnetic fields.It shows strong anisotropy of crystals in high magnetic fields.