Modulation of persistent photoconductivity by electric-field-controlled strain in thin films of La0.39Pr0.24Ca0.37MnO3

Abstract

Thin films of La 0.39 Pr 0.24 Ca 0.37 MnO 3 (LPCMO) were epitaxially grown on 0.7PbMg 1/3 Nb 2/3 O 3-0.3PbTiO 3 (PMN-PT) substrates. These LPCMO films exhibited low-temperature persistent photoconductivity (PPC) when illuminated by a visible light of 532 nm. Not only the resistance but also PPC were modulated by electric fields across PMN-PT. Detailed analysis and in situ x-ray diffraction indicate that such modulations were mainly due to the change of lattice deformation by applied electric fields via converse piezoelectric effect. It was also found that light and strain influence the phase competition in different ways. V

Effects of residual and tunable strain on the transport properties and electroresistance effects in thin films of La0.39Pr0.24Ca0.37MnO3

“…It has been found that the strain state influences not only the electric conduction and magnetism [19][20][21][22][23][24][25][26]28], but also the magnetorsistance effects and photoconductivity [27,36]. In this study, we found that the strain state also affects the electroresistance effects in LPCMO.…”

“…Thus, the magnetic field . In an electrostrictive material, the strain ε is proportional to E 2 , rather than E. As shown in our previous report [36], when E changes between 0 kV/cm and 10 kV/cm, ∆c/c PMN-PT is found to change linearly with E, indicating a piezoelectric nature of the electric-field-induced strain. Thus, the contribution from electrostriction should be very small.…”

“…Thus, the contribution from electrostriction should be very small. As shown in our previous report [36], due to converse piezoelectric effect, Mills et al [28], the properties of manganites is extremely sensitive to biaxial strain, ε*= 1/2(ε zz -ε xx )= ε zz (1+ν)/4ν for ε xx= ε yy . For a tensile in-plane strain, the in-plane lattice parameter will be stretched and the out-of-plane lattice parameter will be compressed.…”

“…A C C E P T E D ACCEPTED MANUSCRIPT 5 PMNPT (3×5×0.5 mm 3 ) were fabricated by using the pulsed laser deposition (KrF excimer laser) method from a LPCMO target [36]. The base chamber pressure was less than 10 -4 Pa.…”

“…In past years, much work has been devoted to these external-stimuli-induced changes because these studies are helpful for understanding the underlying physics in manganites as well as practical application. However, there have been very limited reports on the interaction between different external perturbations [24,36]. Especially, the influences of strain on the electroresistance effects have been rarely addressed [37].…”