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Abnormal percolative transport and colossal electroresistance induced by anisotropic strain in (011)-Pr(0.7)(Ca(0.6)Sr(0.4))(0.3)MnO₃/PMN-PT heterostructure.

Zhao YY, Wang J, Kuang H, Hu FX, Zhang HR, Liu Y, Zhang Y, Wang SH, Wu RR, Zhang M, Bao LF, Sun JR, Shen BG - Sci Rep (2014)

Bottom Line: By introducing an electric-field-induced in-plane anisotropic strain-field in a phase separated PCSMO film, we stimulate a significant inverse thermal hysteresis (~ -17.5 K) and positive colossal electroresistance (~11460%), which is found to be crucially orientation-dependent and completely inconsistent with the well accepted conventional percolation picture.Meanwhile, it is found that the positive colossal electroresistance should be ascribed to the coactions between the anisotropic strain and the polarization effect from the poling of the substrate which leads to orientation and bias-polarity dependencies for the colossal electroresistance.This work unambiguously evidences the indispensable role of the anisotropic strain-field in driving the abnormal percolative transport and provides a new perspective for well understanding the percolation mechanism in inhomogeneous systems.

View Article: PubMed Central - PubMed

Affiliation: Beijing National Laboratory for Condensed Matter Physics and State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.

ABSTRACT
Abnormal percolative transport in inhomogeneous systems has drawn increasing interests due to its deviation from the conventional percolation picture. However, its nature is still ambiguous partly due to the difficulty in obtaining controllable abnormal percolative transport behaviors. Here, we report the first observation of electric-field-controlled abnormal percolative transport in (011)-Pr(0.7)(Ca(0.6)Sr(0.4))(0.3)MnO3/0.7Pb(Mg(1/3)Nb(2/3))O3-0.3PbTiO3 heterostructure. By introducing an electric-field-induced in-plane anisotropic strain-field in a phase separated PCSMO film, we stimulate a significant inverse thermal hysteresis (~ -17.5 K) and positive colossal electroresistance (~11460%), which is found to be crucially orientation-dependent and completely inconsistent with the well accepted conventional percolation picture. Further investigations reveal that such abnormal inverse hysteresis is strongly related to the preferential formation of ferromagnetic metallic domains caused by in-plane anisotropic strain-field. Meanwhile, it is found that the positive colossal electroresistance should be ascribed to the coactions between the anisotropic strain and the polarization effect from the poling of the substrate which leads to orientation and bias-polarity dependencies for the colossal electroresistance. This work unambiguously evidences the indispensable role of the anisotropic strain-field in driving the abnormal percolative transport and provides a new perspective for well understanding the percolation mechanism in inhomogeneous systems.

No MeSH data available.


Related in: MedlinePlus

The temperature dependent electroresistance, ΔR/R = (R(E)-R(0))/R(0), under a bias of +10 kV/cm along in-plane (a) [100] and (b)  directions.The insets plot the results under a negative bias of −10 kV/cm for corresponding directions. The arrows indicate the directions of sweeping temperature.
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f4: The temperature dependent electroresistance, ΔR/R = (R(E)-R(0))/R(0), under a bias of +10 kV/cm along in-plane (a) [100] and (b) directions.The insets plot the results under a negative bias of −10 kV/cm for corresponding directions. The arrows indicate the directions of sweeping temperature.

Mentions: Upon application of bias electric-field of ±10 kV/cm, the percolative behavior of the film, especially in the in-plane [100] direction, exhibits novel changes. First of all, with applying an electric field of +10 kV/cm on the PMN-PT substrate, the IMT temperature (TIMT, the peak temperature on heating as defined above) along the [100] direction shows a shift about ~14 K towards lower temperature (Fig. 3(a)). More importantly, the resistance measured along the [100] direction dramatically increases in the heating branch while slightly decreases in the cooling branch around TIMT. Such a response of the resistance to the electric bias field causes the heating branch rises to exceed the cooling one, resulting in novel phenomena: inverse thermal hysteresis and positive colossal electroresistance. It is determined, from the curves in Fig. 3(a), that the thermal hysteresis of the film in the direction of [100] changes from 4.5 K to −17.5 K (indicated by red arrows) as +10 kV/cm electric field is applied. Such abnormal inverse thermal hysteresis cannot be explained solely by conventional percolation picture, which predicts a normal hysteresis between the cooling and heating branches. To further quantify the influence of the electric field on percolative transport, we calculate the electroresistance, ΔR/R = (R(E)-R(0))/R(0), along two in-plane directions, as shown in Fig. 4(a) and (b). It is found that, with the application of bias field +10 kV/cm, the positive electroresistance along the in-plane [100] direction reaches a maximum of ~11460% at 95 K in the heating process (see Fig. 4(a)). To the best of our knowledge, such positive colossal electroresistance is firstly reported in the phase-separated manganite systems. The value exceeds that of most manganite systems previously reported. It was reported that, for a ferroelectric field effect transistor structure of La0.8Ca0.2MnO3-Pb(Zr0.2Ti0.8)O3, a maximal resistive modulation could reach +20% with a large electric field of +150 KV/cm at room temperature due to the field-induced polarization effect26. By using field-induced strain effect in (001)-La0.7Sr0.3MnO3/Pb(Mg1/3Nb2/3)O3-PbTiO3 structure, C. Thiele et al.25 observed a negative electroresistance up to −9% at 300 K for a in-plane contraction of 0.1% induced by a electric field of 12.5 kV/cm. More recently, by combining the field-induced polarization and strain effect, Tao Jiang et al.24 obtained a negative resistive modulation of −53.2% with E = 12 kV/cm at 140 K in La0.7Ca0.3MnO3/SrTiO3/Pb(Mg1/3Nb2/3)O3-PbTiO3. In present work, the observed positive colossal electroresistance and different temperature dependency of the electroresistance in cooling and heating branches (see Fig. 4(a)) suggest that the electric field may have a different influence on the topological structure of coexisting phases in the [100] direction during cooling and heating processes, considering that the COI phase has a much higher resistivity than the FMM one. Moreover, experiments with a negative bias field of −10 kV/cm was also performed. Similar inverse hysteresis ΔT and positive colossal electroresistance ΔR/R are observed for the in-plane [100] direction (see the insets of Fig. 3(a) and 4(a)), suggesting that the electric-field-induced strain field may play a critical role in driving the abnormal percolative transport behaviors. The only differences from the case with applying positive bias are that the ΔT width (~ −8.5 K) and ΔR/R magnitude (~2130%) becomes smaller, indicating that polarization effect also affect the electric transport.


Abnormal percolative transport and colossal electroresistance induced by anisotropic strain in (011)-Pr(0.7)(Ca(0.6)Sr(0.4))(0.3)MnO₃/PMN-PT heterostructure.

Zhao YY, Wang J, Kuang H, Hu FX, Zhang HR, Liu Y, Zhang Y, Wang SH, Wu RR, Zhang M, Bao LF, Sun JR, Shen BG - Sci Rep (2014)

The temperature dependent electroresistance, ΔR/R = (R(E)-R(0))/R(0), under a bias of +10 kV/cm along in-plane (a) [100] and (b)  directions.The insets plot the results under a negative bias of −10 kV/cm for corresponding directions. The arrows indicate the directions of sweeping temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4233337&req=5

f4: The temperature dependent electroresistance, ΔR/R = (R(E)-R(0))/R(0), under a bias of +10 kV/cm along in-plane (a) [100] and (b) directions.The insets plot the results under a negative bias of −10 kV/cm for corresponding directions. The arrows indicate the directions of sweeping temperature.
Mentions: Upon application of bias electric-field of ±10 kV/cm, the percolative behavior of the film, especially in the in-plane [100] direction, exhibits novel changes. First of all, with applying an electric field of +10 kV/cm on the PMN-PT substrate, the IMT temperature (TIMT, the peak temperature on heating as defined above) along the [100] direction shows a shift about ~14 K towards lower temperature (Fig. 3(a)). More importantly, the resistance measured along the [100] direction dramatically increases in the heating branch while slightly decreases in the cooling branch around TIMT. Such a response of the resistance to the electric bias field causes the heating branch rises to exceed the cooling one, resulting in novel phenomena: inverse thermal hysteresis and positive colossal electroresistance. It is determined, from the curves in Fig. 3(a), that the thermal hysteresis of the film in the direction of [100] changes from 4.5 K to −17.5 K (indicated by red arrows) as +10 kV/cm electric field is applied. Such abnormal inverse thermal hysteresis cannot be explained solely by conventional percolation picture, which predicts a normal hysteresis between the cooling and heating branches. To further quantify the influence of the electric field on percolative transport, we calculate the electroresistance, ΔR/R = (R(E)-R(0))/R(0), along two in-plane directions, as shown in Fig. 4(a) and (b). It is found that, with the application of bias field +10 kV/cm, the positive electroresistance along the in-plane [100] direction reaches a maximum of ~11460% at 95 K in the heating process (see Fig. 4(a)). To the best of our knowledge, such positive colossal electroresistance is firstly reported in the phase-separated manganite systems. The value exceeds that of most manganite systems previously reported. It was reported that, for a ferroelectric field effect transistor structure of La0.8Ca0.2MnO3-Pb(Zr0.2Ti0.8)O3, a maximal resistive modulation could reach +20% with a large electric field of +150 KV/cm at room temperature due to the field-induced polarization effect26. By using field-induced strain effect in (001)-La0.7Sr0.3MnO3/Pb(Mg1/3Nb2/3)O3-PbTiO3 structure, C. Thiele et al.25 observed a negative electroresistance up to −9% at 300 K for a in-plane contraction of 0.1% induced by a electric field of 12.5 kV/cm. More recently, by combining the field-induced polarization and strain effect, Tao Jiang et al.24 obtained a negative resistive modulation of −53.2% with E = 12 kV/cm at 140 K in La0.7Ca0.3MnO3/SrTiO3/Pb(Mg1/3Nb2/3)O3-PbTiO3. In present work, the observed positive colossal electroresistance and different temperature dependency of the electroresistance in cooling and heating branches (see Fig. 4(a)) suggest that the electric field may have a different influence on the topological structure of coexisting phases in the [100] direction during cooling and heating processes, considering that the COI phase has a much higher resistivity than the FMM one. Moreover, experiments with a negative bias field of −10 kV/cm was also performed. Similar inverse hysteresis ΔT and positive colossal electroresistance ΔR/R are observed for the in-plane [100] direction (see the insets of Fig. 3(a) and 4(a)), suggesting that the electric-field-induced strain field may play a critical role in driving the abnormal percolative transport behaviors. The only differences from the case with applying positive bias are that the ΔT width (~ −8.5 K) and ΔR/R magnitude (~2130%) becomes smaller, indicating that polarization effect also affect the electric transport.

Bottom Line: By introducing an electric-field-induced in-plane anisotropic strain-field in a phase separated PCSMO film, we stimulate a significant inverse thermal hysteresis (~ -17.5 K) and positive colossal electroresistance (~11460%), which is found to be crucially orientation-dependent and completely inconsistent with the well accepted conventional percolation picture.Meanwhile, it is found that the positive colossal electroresistance should be ascribed to the coactions between the anisotropic strain and the polarization effect from the poling of the substrate which leads to orientation and bias-polarity dependencies for the colossal electroresistance.This work unambiguously evidences the indispensable role of the anisotropic strain-field in driving the abnormal percolative transport and provides a new perspective for well understanding the percolation mechanism in inhomogeneous systems.

View Article: PubMed Central - PubMed

Affiliation: Beijing National Laboratory for Condensed Matter Physics and State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.

ABSTRACT
Abnormal percolative transport in inhomogeneous systems has drawn increasing interests due to its deviation from the conventional percolation picture. However, its nature is still ambiguous partly due to the difficulty in obtaining controllable abnormal percolative transport behaviors. Here, we report the first observation of electric-field-controlled abnormal percolative transport in (011)-Pr(0.7)(Ca(0.6)Sr(0.4))(0.3)MnO3/0.7Pb(Mg(1/3)Nb(2/3))O3-0.3PbTiO3 heterostructure. By introducing an electric-field-induced in-plane anisotropic strain-field in a phase separated PCSMO film, we stimulate a significant inverse thermal hysteresis (~ -17.5 K) and positive colossal electroresistance (~11460%), which is found to be crucially orientation-dependent and completely inconsistent with the well accepted conventional percolation picture. Further investigations reveal that such abnormal inverse hysteresis is strongly related to the preferential formation of ferromagnetic metallic domains caused by in-plane anisotropic strain-field. Meanwhile, it is found that the positive colossal electroresistance should be ascribed to the coactions between the anisotropic strain and the polarization effect from the poling of the substrate which leads to orientation and bias-polarity dependencies for the colossal electroresistance. This work unambiguously evidences the indispensable role of the anisotropic strain-field in driving the abnormal percolative transport and provides a new perspective for well understanding the percolation mechanism in inhomogeneous systems.

No MeSH data available.


Related in: MedlinePlus