Park, Dae-Sung, Rees, Gregory J., Wang, Haiyuan, Rata, Diana, Morris, Andrew J., Maznichenko, Igor V., Ostanin, Sergey, Bhatnagar, Akash, Choi, Chel-Jong, Jonsson, R. D., Kaufmann, Kai, Kashtiban, Reza, Walker, Marc, Chiang, C.-T., Thorsteinsson, Einar B., Luo, Zhengdong, Park, In-Sung, Hanna, John V., Mertig, I., Doerr, Kathrin, Gislason, Haflidi P., McConville, Chris F.
Electromagnetic functionalization of wide-bandgap dielectric oxides by boron interstitial doping
Advanced Materials 30, (39),pp 1802025/1-9 (2018)
A surge in interest of oxide-based materials is testimony for their potential utility in a wide array of device applications and offers a fascinating landscape for tuning the functional properties through a variety of physical and chemical parameters. In particular, selective electronic/defect doping has been demonstrated to be vital in tailoring novel functionalities, not existing in the bulk host oxides. Here, an extraordinary interstitial doping effect is demonstrated centered around a light element, boron (B). The host matrix is a novel composite system, made from discrete bulk LaAlO3:LaBO3 compounds. The findings show a spontaneous ordering of the interstitial B cations within the host LaAlO3 lattices, and subsequent spin-polarized charge injection into the neighboring cations. This leads to a series of remarkable cation-dominated electrical switching and high-temperature ferromagnetism. Hence, the induced interstitial doping serves to transform a nonmagnetic insulating bulk oxide into a ferromagnetic ionic-electronic conductor. This unique interstitial B doping effect upon its control is proposed to be as a general route for extracting/modifying multifunctional properties in bulk oxides utilized in energy and spin-based applications.