Nonlinear optical and magnetic properties of BiFeO3 harmonic nanoparticles

• Published in: Journal of applied physics Vol. 116; no. 11
• Main Authors: Schwung, Sebastian, Rogov, Andrii, Clarke, Gareth, Joulaud, Cécile, Magouroux, Thibaud, Staedler, Davide, Passemard, Solène, Jüstel, Thomas, Badie, Laurent, Galez, Christine, Wolf, Jean Pierre, Volkov, Yuri, Prina-Mello, Adriele, Gerber-Lemaire, Sandrine, Rytz, Daniel, Mugnier, Yannick, Bonacina, Luigi, Le Dantec, Ronan
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 21.09.2014
• Subjects: Applied physics; Biomarkers; Bismuth ferrite; Condensed Matter; Diagnostic software; Diagnostic systems; Magnetic properties; Materials Science; Nanocrystals; Nanoparticles; Nonlinear optics; Nonlinear response; Optical properties; Optics; Physics; Polarization; Rayleigh scattering; Second harmonic generation
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4895836

Second Harmonic Generation (SHG) from BiFeO3 nanocrystals is investigated for the first time to determine their potential as biomarkers for multiphoton imaging. Nanocrystals are produced by an auto-combustion method with 2-amino-2-hydroxymethyl-propane-1,3-diol as a fuel. Stable colloidal suspensions with mean particle diameters in the range 100–120 nm are then obtained after wet-milling and sonication steps. SHG properties are determined using two complementary experimental techniques, Hyper Rayleigh Scattering and nonlinear polarization microscopy. BiFeO3 shows a very high second harmonic efficiency with an averaged 〈d〉 coefficient of 79 ± 12 pm/V. From the nonlinear polarization response of individual nanocrystals, relative values of the independent dij coefficients are also determined and compared with recent theoretical and experimental studies. Additionally, the particles show a moderate magnetic response, which is attributed to γ-Fe2O3 impurities. A combination of high nonlinear optical efficiency and magnetic response within the same particle is of great interest for future bio-imaging and diagnostic applications.