Low-temperature grapho-epitaxial La-substituted BiFeO3 on metallic perovskite

Abstract

Bismuth ferrite has garnered considerable attention as a promising candidate for magnetoelectric spin-orbit coupled logic-in-memory. As model systems, epitaxial BiFeO3 thin films have typically been deposited at relatively high temperatures (650–800 °C), higher than allowed for direct integration with silicon-CMOS platforms. Here, we circumvent this problem by growing lanthanum-substituted BiFeO3 at 450 °C (which is reasonably compatible with silicon-CMOS integration) on epitaxial BaPb0.75Bi0.25O3 electrodes. Notwithstanding the large lattice mismatch between the La-BiFeO3, BaPb0.75Bi0.25O3, and SrTiO3 (001) substrates, all the layers in the heterostructures are well ordered with a [001] texture. Polarization mapping using atomic resolution STEM imaging and vector mapping established the short-range polarization ordering in the low temperature grown La-BiFeO3. Current-voltage, pulsed-switching, fatigue, and retention measurements follow the characteristic behavior of high-temperature grown La-BiFeO3, where SrRuO3 typically serves as the metallic electrode. These results provide a possible route for realizing epitaxial multiferroics on complex-oxide buffer layers at low temperatures and opens the door for potential silicon-CMOS integration.

Unfolding the Challenges To Prepare Single Crystalline Complex Oxide Membranes by Solution Processing

“…On the other hand, the use of solvent-free chemical deposition techniques such as atomic layer deposition could be an attractive route toward all-chemical complex oxide membranes. Finally, further investigations on the interplay between strain gradient, phase distortion, and superflexibility in these complex oxides could offer many practical applications in sensors, memories, spintronics, electronic skins, and self-powered devices. − , These broad range of possibilities could also be extended to other piezoelectric, ferroelectric, and multiferroic perovskite oxides anticipating a rich playground for complex oxide freestanding membranes to create new functional materials.…”

Dependence of the Structural and Magnetic Properties on the Growth Sequence in Heterostructures Designed by YbFeO3 and BaFe12O19

“…This represents the most common approach used for altering the strain at the interface between the epitaxial film and the substrate and the resulting magnetic and electric properties [ 27 , 28 ]. Interfacial effects such as epitaxial strain [ 29 ], interface quality (i.e., defect, roughness, sharpness) [ 30 , 31 , 32 ], interdiffusion, and chemical intermixing [ 33 , 34 ] in multiferroic heterostructures have attracted tremendous attention for tuning and understanding the structure–property relationships as they allow one to control the magnetic interaction [ 35 ], spin ordering [ 36 , 37 ], and coupling across heterointerfaces, including ferromagnetic (FM)/antiferromagnetic (AFM) bilayer systems [ 30 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. Several studies reported the occurrence of an exchange interaction based on the exchange bias (EB) at the interface of FM/AFM heterostructures.…”