Multiferroic LuFe2O4 (LFO) exhibits three-dimensional (3D) charge order below T-CO similar to 350 K and strong electroresistance (ER) above a static threshold field E-th. By measuring simultaneously, in LFO single crystals, the dc current and the far-infrared reflectivity along different axes, we do not detect any insulator-to-metal transition above E-th. Combined current-temperature measurements confirm that the ER is due to self-heating of LFO, as recently reported. The data can be fit by the standard activation law for an intrinsic semiconductor, with a gap value Delta = 0.57 eV. This value is consistent with that of the optical gap reported for LFO in the literature.
Infrared and transport properties of LuFe2O4 under electric fields / Vitucci, FRANCESCO MARIA; Nucara, Alessandro; Mirri, Chiara; Nicoletti, Daniele; Ortolani, Michele; U., Schade; Calvani, Paolo. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 84:(2011), pp. 153105-1-153105-4. [10.1103/physrevb.84.153105]
Infrared and transport properties of LuFe2O4 under electric fields
VITUCCI, FRANCESCO MARIA;NUCARA, Alessandro;MIRRI, CHIARA;NICOLETTI, DANIELE;ORTOLANI, MICHELE;CALVANI, Paolo
2011
Abstract
Multiferroic LuFe2O4 (LFO) exhibits three-dimensional (3D) charge order below T-CO similar to 350 K and strong electroresistance (ER) above a static threshold field E-th. By measuring simultaneously, in LFO single crystals, the dc current and the far-infrared reflectivity along different axes, we do not detect any insulator-to-metal transition above E-th. Combined current-temperature measurements confirm that the ER is due to self-heating of LFO, as recently reported. The data can be fit by the standard activation law for an intrinsic semiconductor, with a gap value Delta = 0.57 eV. This value is consistent with that of the optical gap reported for LFO in the literature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
