Low expansion in [(Fe0.9Co0.1)0.72B0.24Nb0.04]95.5Y4.5 bulk metallic glass

We present a systematic study to clarify the origin of nonlinear I-V characteristics widely observed in charge ordered oxides. The experiments performed on the charge ordered YbFe2O4 single crystals demonstrate that the I-V behavior strongly depends on the measurement parameters, such as the width and strength of applied voltage/current pulse, the time interval between two subsequent pulses, and the time delay before reading a data. Correspondingly, three regimes are identified: (i) steep nonlinear I-V behavior induced by self-heating when the pulse width is big and/or the time interval is short; (ii) smooth nonlinear I-V characteristic in the low field range when the electric pulse width is small and the time interval is long enough, owing to sliding of charge density wave; (iii) abrupt collapse of charge order/charge density wave at high electric fields. A proper measurement scheme must be employed in order to distinguish the intrinsic effects associated with electric field modulation of charge order from the extrinsic self-heating effect. (C) 2012 American Institute of Physics. [doi:10.1063/1.3681184]