Direct measurement of mechanical properties of (Pb,La)TiO3 ferroelectric thin films using nanoindentation techniques

2001 ◽  
Vol 16 (4) ◽  
pp. 993-1002 ◽  
Author(s):  
M. Algueró ◽  
A. J. Bushby ◽  
M. J. Reece
Keyword(s):  
Thin Films ◽  
Plastic Deformation ◽  
Lead Titanate ◽  
Mechanical Response ◽  
High Spatial Resolution ◽  
Ferroelectric Thin Films ◽  
Intergranular Porosity ◽  
Major Mechanism ◽  
Wall Movement ◽  
Film Substrate

A procedure using nanoindentation with spherical tipped indenters is presented that allows separation of elastic, anelastic, and plastic contributions to the deformation of thin films. The procedure was demonstrated on a range of lanthanum-modified lead titanate (Pb,La)TiO3 (PTL) ferroelectric thin films. Indentation stiffness coefficients ranging from 110 to 147 GPa have been obtained depending on the microstructure and orientation of the PTL films. This coefficient was equivalent to (and so, can be directly compared with) Young's modulus of a nontextured, unpoled ceramic when films do not present preferred orientation. The trends of the anelastic contribution with the thickness, structure, microstructure, and stress level at the film/substrate interface of the films were consistent with it being produced by ferroelastic domain wall movement. Pore compaction was a major mechanism of plastic deformation for the PTL films. Grain size also affected plastic deformation, probably as a consequence of its correlation with intergranular porosity. The technique has a high spatial resolution (contact area < 10 μm2 for the results presented here), which allowed the mechanical homogeneity of the films to be studied and inhomogeneities to be identified from their mechanical response (elastic, anelastic, and plastic).

Shear Properties of Polymer Films Within Confined Contacts

2005 ◽  
Author(s):  
E. Gacoin ◽  
C. Fretigny ◽  
A. Chateauminois
Keyword(s):  
Plastic Deformation ◽  
Hydrostatic Pressure ◽  
Polymer Films ◽  
Mechanical Response ◽  
Contact Stiffness ◽  
Shear Moduli ◽  
Lateral Contact ◽  
Contact Models ◽  
Film Substrate ◽  
Material Compressibility

Approximate contact models for film/substrate systems have been developed and validated in order to determine the shear moduli of mechanically confined films using lateral contact stiffness measurements. This approach allowed to discuss the effects of material compressibility, hydrostatic pressure and plastic deformation on the mechanical response of thin polymers films within macroscopic contacts.

The role of nanoporosity on the local piezo and ferroelectric properties of lead titanate thin films

2015 ◽  
Vol 3 (5) ◽  
pp. 1035-1043 ◽  
Author(s):  
Alichandra Castro ◽  
Paula Ferreira ◽  
Brian J. Rodriguez ◽  
Paula M. Vilarinho
Keyword(s):  
Thin Films ◽  
Coercive Field ◽  
Lead Titanate ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Films ◽  
Piezoelectric Response ◽  
Nanoporous Films ◽  
Switching Behaviour ◽  
Dense Films

Nanoporous PbTiO3 films present enhanced tetragonality at lower temperatures than respective dense films. Moreover, the porosity present in the nanoporous films allows an increase of the local piezoelectric response and a decrease of the local coercive field. As a result, these nanoporous films might be used to improve the switching behaviour of ferroelectric thin films.

Frequency Spectra of Fatigue of PZT and other Ferroelectric Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
Xiaofeng Du ◽  
I-Wei Chen
Keyword(s):  
Thin Films ◽  
Frequency Response ◽  
High Frequency ◽  
Fatigue Behavior ◽  
Ferroelectric Thin Films ◽  
Physical Models ◽  
Fatigue Properties ◽  
Frequency Spectra ◽  
Wall Movement ◽  
Measuring Frequency

ABSTRACTPolarization and polarization fatigue of PZT and other ferroelectric thin films have been studied via the frequency spectra of D-E hysteresis. The coercive field (Ec) of PZT thin films has been found strongly dependent on the measuring frequency, while a relatively flat frequency response is observed with SrBi2Nb2O9 thin films. The different fatigue behavior can be attributed to such a difference in the frequency response. Physical models have been suggested to for domain wall movement in PZT and SrBi2Nb2O9 thin films. Based on these observations, a methodology has been proposed to evaluate the high frequency and fatigue properties of ferroelectric thin films.

Ferroelectric thin films of calcium modified lead titanate by sol-gel processing

1994 ◽  
Vol 13 (24) ◽  
pp. 1804-1805 ◽  
Author(s):  
R. Sirera ◽  
M. L. Calzada ◽  
F. Carmona ◽  
B. Jim�nez
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
Gel Processing

Correlation of film stress and the mechanical response of Au thin films

1996 ◽  
Vol 54 ◽  
pp. 856-857
Author(s):  
K.F. Jarausch ◽  
J.E. Houston ◽  
P.E. Russell
Keyword(s):  
Thin Films ◽  
Mechanical Response ◽  
Semiconductor Industry ◽  
Maximum Shear Stress ◽  
Effective Elastic Modulus ◽  
Film Stress ◽  
Strain Effect ◽  
Stress And Strain ◽  
Au Thin Films ◽  
Film Substrate

The investigation of the mechanical properties of nanostructured materials is critical to the continuing development of thin film technology. For example, the semiconductor industry must understand how stress and strain effect the electronic properties of superlattices and cause the delamination of metal interconnect films. A variety of nano-indentation techniques have been developed as tools to investigate the mechanical behavior of thin films. In a previous study the interfacial force microscope (IFM) was used to survey the mechanical response of 200nm thick Au films deposited on various substrates under various deposition conditions. By combining the methods of contact mechanics and classic indentation techniques, quantitative investigations of the effective elastic modulus and the maximum shear-stress at the plastic threshold were tabulated. The results indicated a large variation in these parameters for the various film/substrates, while the values were consistent over a single film/substrate. The observed variation could be explained by several factors: differences in the films morphology, adhesion to the substrate, or residual stress.

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