scholarly journals Hysteresis-Free Piezoresponse in Thermally Strained Ferroelectric Barium Titanate Films

2021 ◽  
Vol 2 (1) ◽  
pp. 17-23
Author(s):  
Marina Tyunina ◽  
Jan Miksovsky ◽  
Tomas Kocourek ◽  
Alexandr Dejneka

Modern technology asks for thin films of sustainable piezoelectrics, whereas electro-mechanical properties of such films are poorly explored and controlled. Here, dynamic and quasi-static polarization, dielectric, and piezoelectric responses were experimentally studied in thin-film stacks of barium titanate sandwiched between electrodes and grown on top of strontium titanate substrate. Accurate piezoelectric characterization was secured by using double beam interferometric technique. All out-of-plane responses were found to be hysteresis-free. Effective piezoelectric coefficient ~50 pm/V and linear strain-voltage characteristic were achieved. The observed behavior was ascribed to field induced out-of-plane polarization, whereas spontaneous polarization is in-plane due to in-plane tensile thermal strain. Hysteresis-free linear piezoresponse was anticipated in thin films on commercial silicon substrates, enabling large thermal strain.

1999 ◽  
Vol 14 (3) ◽  
pp. 688-697 ◽  
Author(s):  
S. Jayaraman ◽  
R. L. Edwards ◽  
K. J. Hemker

Polycrystalline silicon thin films (polysilicon) have been deposited on single crystalline silicon substrates, and square and rectangular windows have been etched into these substrates using standard micromachining techniques. Pressure-displacement curves of the resulting polysilicon membranes have been obtained for these geometries, and this data has been used to determine the elastic constants E and v. The microstructural features of the films have been investigated by transmission electron microscopy (TEM) and x-ray diffraction. The grains were observed to be columnar and were found to have a 〈011〉 out-of-plane texture and a random in-plane grain orientation. A probabilistic model of the texture has been used to calculate the bounds of the elastic constants in the thin films. The results obtained from bulge testing (E = 162 ± 4 GPa and v = 0.20 ± 0.03) fall in the wide range of values previously reported for polysilicon and are in good agreement with the microsample tensile measurements conducted on films deposited in the same run as the present study (168 ± 2 GPa and 0.22 ± 0.01) and the calculated values of the in-plane moduli for 〈1103〉 textured films (E = 163.0–165.5 GPa and v = 0.221–0.239).


1994 ◽  
Vol 346 ◽  
Author(s):  
M.I. Yanovskaya ◽  
N.M. Kotova ◽  
I.E. Obvintseva ◽  
E.P. Turevskaya ◽  
N.Ya. Turova ◽  
...  

ABSTRACTPreparation of complex oxides in the form of powders and thin films from metal alkoxides is discussed. Most attention is paid to ferroelectric and related materials ‐ complex titanates and zirconates. Techniques for preparation of high‐purity morphologically homogeneous powders Ti2, ZrO2 barium titanate and BaTiO3‐based solid solutions, MgTiO3, Bi2WO6, Bi2MoO6 are proposed and discussed wilh respect to their application in ceramics technology. The solutions prepared electrochemically in methoxyethanol were widely used for formation of thin films, e.g. Y2O3‐stabilized ZrO2 and ρζγ solid solutions on Pt‐coated silicon substrates.


1996 ◽  
Vol 459 ◽  
Author(s):  
Joseph F. Shepard ◽  
Paul J. Moses ◽  
Susan Trolier-McKinstry

ABSTRACTThis paper describes a new technique by which the d31 coefficient of piezoelectric thin films can be characterized. Silicon substrates coated with lead-zirconate titanate (PZT) are flexed while clamped in a uniform load rig. When stressed, the PZT film produces an electric charge which is monitored together with the change in applied load. The mechanical stress and thus the transverse piezoelectric coefficient can then be calculated. Experiments were conducted as a function of poling field strength and poling time. Results are dependent upon the value of applied stress, which itself is dependent upon the mechanical properties of the silicon substrate. Because the substrate is anisotropie, limiting d31 values were calculated. In general, d31 was found to be ∼20 pC/N for field strengths above 130 kV/cm and poling times of less than 1 minute, d31 was increased more than a factor of three, to ∼77 pC/N, when poled at 200 kV/cm for ∼21 hours.


2019 ◽  
Vol 201 (1) ◽  
pp. 86-93
Author(s):  
S. Laxmi Priya ◽  
V. Kumar ◽  
Isaku Kanno

In this study, we report the effect of Zr/Sn ratio on the Antiferroelectric (AFE) → Ferroelectric (FE) phase transition and transverse piezoelectric characteristics on AFE thin films of compositions having the general formula Pb0.97La0.02(Zr1-x+ySnxTiy)O3, where y = 0.10 and 0.10 ≤ x ≤ 0.15 along the phase boundary in the ternary system Pb(Zr0.50Ti0.50)O3-Pb(Zr0.50Sn0.50)O3-PbZrO3. Thin films having a thickness of 2.0 µm were fabricated on platinised silicon substrates by sol–gel method. Data obtained from dielectric, ferroelectric and structural studies have been combined to explain the mechanism of AFE → FE switching.


2018 ◽  
Author(s):  
K. A. Rubin ◽  
W. Jolley ◽  
Y. Yang

Abstract Scanning Microwave Impedance Microscopy (sMIM) can be used to characterize dielectric thin films and to quantitatively discern film thickness differences. FEM modeling of the sMIM response provides understanding of how to connect the measured sMIM signals to the underlying properties of the dielectric film and its substrate. Modeling shows that sMIM can be used to characterize a range of dielectric film thicknesses spanning both low-k and medium-k dielectric constants. A model system consisting of SiO2 thin films of various thickness on silicon substrates is used to illustrate the technique experimentally.


MRS Advances ◽  
2016 ◽  
Vol 1 (37) ◽  
pp. 2635-2640 ◽  
Author(s):  
Adele Moatti ◽  
Reza Bayati ◽  
Srinivasa Rao Singamaneni ◽  
Jagdish Narayan

ABSTRACTBi-epitaxial VO2 thin films with [011] out-of-plane orientation were integrated with Si(100) substrates through TiO2/TiN buffer layers. At the first step, TiN is grown epitaxially on Si(100), where a cube-on-cube epitaxy is achieved. Then, TiN was oxidized in-situ ending up having epitaxial r-TiO2. Finally, VO2 was deposited on top of TiO2. The alignment across the interfaces was stablished as VO2(011)║TiO2(110)║TiN(100)║Si(100) and VO2(110) /VO2(010)║TiO2(011)║TiN(112)║Si(112). The inter-planar spacing of VO2(010) and TiO2(011) equal to 2.26 and 2.50 Å, respectively. This results in a 9.78% tensile misfit strain in VO2(010) lattice which relaxes through 9/10 alteration domains with a frequency factor of 0.5, according to the domain matching epitaxy paradigm. Also, the inter-planar spacing of VO2(011) and TiO2(011) equals to 3.19 and 2.50 Å, respectively. This results in a 27.6% compressive misfit strain in VO2(011) lattice which relaxes through 3/4 alteration domains with a frequency factor of 0.57. We studied semiconductor to metal transition characteristics of VO2/TiO2/TiN/Si heterostructures and established a correlation between intrinsic defects and magnetic properties.


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