Antiferromagnetic transitions in tetragonal-like BiFeO3

TitleAntiferromagnetic transitions in tetragonal-like BiFeO3
Publication TypeJournal Article
Year of Publication2012
AuthorsMacDougall GJ, Christen HM, Siemons W, Biegalski MD, Zarestky JL, Liang S, Dagotto E, Nagler SE
Journal TitlePhysical Review B
Date Published03
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000301705500001
Keywordsepitaxy, ferroelectricity, magnetism, neutron-diffraction, phases, polarization, room-temperature, strain, thin-films

Recent studies have reported the existence of an epitaxially stabilized tetragonal-like ("T-like") monoclinic phase in BiFeO3 thin films with high levels of compressive strain. While their structural and ferroelectric properties are different from those of rhombohedral-like ("R-like") films with lower levels of strain, little information exists on magnetic properties. Here, we report on a detailed neutron scattering study of a nearly phase-pure film of T-like BiFeO3. By tracking the temperature dependence and relative intensity of several superstructure peaks in the reciprocal lattice cell, we confirm antiferromagnetism with largely G-type character and T-N = 324 K, significantly below a structural phase transition at 375 K, contrary to previous reports. Evidence for a second transition, possibly a minority magnetic phase with C-type character, is also reported with T-N = 260 K. The coexistence of the two magnetic phases in T-like BiFeO3 and the difference in ordering temperatures between R-like and T-like systems is explained through simple Fe-O-Fe bond distance considerations.

URL<Go to ISI>://WOS:000301705500001
Alternate JournalPhys. Rev. B