| مستخلص: |
Bismuth ferrite (BiFeO3) is a widely studied material,because of its interesting multiferroic properties. Bismuth self-limitinggrowth of single-phase BiFeO3(BFO) has previously beenachieved using molecular beam epitaxy (MBE), but the growth of BFOby chemical vapor deposition (CVD) has proved to be very challenging,because of the volatile nature of bismuth. The growth window regardingtemperature, pressure, and precursor flow rates that will give a pureperovskite BFO phase is normally very small. In this work, we havestudied the metal–organic CVD (MOCVD) growth of epitaxial BFOthin films on SrTiO3substrates and found that by carefullycontrolling the amount of the iron precursor, Fe(thd)3(wherethd = 2,2,6,6 tetra-methyl-3,5-heptanedionate), we were able to achievebismuth self-liming growth, for the first time. The effect of thevolume of the bismuth and iron precursors injected on the growth ofBFO thin films is reported, and it has been found that the phase-purefilms can be prepared when the Bi/Fe ratios are between 1.33 and 1.81under temperature and pressure conditions of 650 °C and 10 mbar,respectively, and where the O2gas flow was kept constantto 1000 sccm out of a total gas flow of 3000 sccm. Piezoresponse forcemicroscopy (PFM) studies demonstrate the presence of bipolar switchingin ultrathin BFO films. [ABSTRACT FROM AUTHOR] |