Flux Method Growth and Structure and Properties Characterization of Rare-Earth Iron Oxides Lu1−x Scx FeO3 Single Crystals

Abstract

Perovskite rare-earth ferrites (REFeO3 ) have attracted great attention for their high ferroelec-tric and magnetic transition temperatures, strong magnetoelectric coupling, and electric polarization. We report on the flux method growth of rare-earth iron oxide Lu1−x Scx FeO3 single crystals through a K2 CO3-B2 O3-Bi2 O3 mixture as a flux solution, and give a detailed characterization of the microstruc-ture, magnetism, and ferroelectric properties. X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) measurements revealed that the obtained single crystals can be designated to three different crystal structures of different chemical compositions, that is, Lu0.96 Sc0.04 FeO3 (per-ovskite phase), Lu0.67 Sc0.33 FeO3 (hexagonal phase), and Lu0.2 Sc0.8 FeO3 (bixbyite phase), respectively. Magnetic measurements indicate that the perovskite Lu0.96 Sc0.04 FeO3 is an anisotropic hard ferromagnetic material with a high Curie transition temperature, the bixbyite Lu0.2 Sc0.8 FeO3 is a low temperature soft ferromagnetic material, and the hexagonal Lu0.67 Sc0.33 FeO3 exhibits multiferroic properties. Lu0.67 Sc0.33 FeO3 possesses a weak ferromagnetic transition at about 162 K. We further investigate the ferroelectric domain structures in hexagonal sample by scanning electron microscope and the characteristic atomic structures in ferroelectric domain walls by atomically resolved scanning transmission electron microscope. Our successful growth of perovskite Lu1−x Scx FeO3 single crystals with distinct crystal structures and stochiometric Lu-Sc substitutions is anticipated to provide a useful ferrites system for furthering exploitation of their multiferroic properties and functionalities.