Related quality links to Physics Papers
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Related quality links to Physics Papers
by Cr6 Sat Jan 24, 2015 11:08 pm
A very good site on SonoChemistry:
http://www.mastersonics.com/documents/
http://www.mastersonics.com/documents/revision_of_the_particle-wave_dualism.pdf
http://www.mastersonics.com/documents/
http://www.mastersonics.com/documents/revision_of_the_particle-wave_dualism.pdf
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Re: Related quality links to Physics Papers
by Cr6 Tue Jan 27, 2015 2:36 am
Electrical Characterisitics of PZT Thin Films
http://www.eecs.berkeley.edu/~hu/PUBLICATIONS/Hu_papers/Hu_JNL/HuC_JNL_114.pdf
Lead zirconium titanate is an intermetallic inorganic compound with the chemical formula Pb[ZrxTi1-x]O3 (0≤x≤1). Also called PZT, it is a ceramic perovskite material that shows a marked piezoelectric effect, which finds practical applications in the area of electroceramics. It is a white solid that is insoluble in all solvents.
Like structurally similar lead scandium tantalate and barium strontium titanate, PZT can be used for manufacture of uncooled staring array infrared imaging sensors for thermographic cameras. Both thin film (usually obtained by chemical vapor deposition) and bulk structures are used. The formula of the material used usually approaches Pb1.1(Zr0.3Ti0.7)O3 (called PZT 30/70). Its properties may be modified by doping it with lanthanum, resulting in lanthanum-doped lead zirconium titanate (PLZT, also called lead lanthanum zirconium titanate), with formula Pb0.83La0.17(Zr0.3Ti0.7)0.9575O3 (PLZT 17/30/70).[6]
https://en.wikipedia.org/wiki/Lead_zirconate_titanate
PHYSICS QUESTIONS
Q. Why is there piezoelectricity?
A. Because some atomic lattice structures have as an essential unit (or "cell") a cubic or rhomboid cage made of atoms, and this cage holds a single semi-mobile ion which has several stable quantum position states inside the cell. The ion's post ion state can be caused to shift by either deforming the cage (applied strain) or by applying and electric field. The coupling between the central ion and the cage provides the basis for transformation of mechanical strain to internal electric field shifts and vice versa.
Q. What is electric field?
A. An electric field is always associated with the presence of electric charges. It fills the space around the charge and is the mechanism of interaction between charges. A test particle with small known charge (Q) placed near a charge concentration will experience an accelerating force (F) due to the field. The value of the electric field (E) at that location is the ratio F/Q (a vector).
Q. What is strain?
A. When a solid object like a rod of length (L) is stretched to a new length (L + delta L), the strain in the rod is defined as the ratio (delta L)/(L). This is a dimensionless measure of stretching or compression often stated as "inches per inch", "millimeters per meter", or "microns per meter (microstrain)" for convenience of visualization.
Q. What is elastic modulus (or Young's modulus) ?
A. A material property of all elastic solids, Young's modulus (Y) is used to describe "stiffness" of materials. When rod or plate of cross section (A) and length (L) is pulled with force (F) resulting in an elongation (delta L), the Young's modulus can be computed as follows: Y = (L/A)*(F/deltaF)
In piezo applications Y is frequently used to estimate the equivalent spring constant of a rod or a plate of material (i.e. that quantity (F/deltaF) that is in contact with a piezo actuator).
Q. What is tensile strength?
A. Tensile strength is the stress (measured in Newtons/m^2 or psi) at which a sample of solid material will break from tension.
Q. What is poling/depoling in piezoceramic materials?
A. The piezoelectric property of ceramics does not arise simply from its chemical composition. In addition to having the proper formulation the piezoceramics must be subjected to a high electric field for a short period of time to force the randomly oriented micro-dipoles into alignment. This alignment by application of high voltage is called "poling". At a later time, if an electric field is applied in the opposite direction it exerts a "dislodging stress" on the micro-dipoles. Low level
applied fields result in no permanent change in the polarization (it bounces back upon removal). Medium fields result in partial degradation of the polarization (with partial loss of properties). High applied fields result in repolarization in the opposite direction.
Q. What is damping?
A. 'Damping' is the term used for the general tendency of vibrating materials or structures to lose some elastic energy to
internal heating or external friction.
Q. Can piezoceramic actuators be used at cryogenic temperatures?
A. Yes. All piezo actuators continue to function right on down to zero degrees Kelvin. This may seem counter-intuitive at first; however, you must remember that the basis for the piezoelectric effect is inter-atomic electric fields, and electric fields are not affected by temperature at all. Quantitatively, the piezo coupling of most common piezoceramics does decrease as temperature drops. At liquid helium temperatures, the motion of most materials drops to about half that measured at room temperature.
Q. What is the pyroelectric effect?
A. The tendency of some materials to exhibit a change in internal electrical polarization state in response to a change in temperature. If the materials are equipped with electrodes on two surfaces, a voltage will arise between the electrodes in response to temperature shifts.
http://mastersonics.com/documents/mmm_basics/general_info/ultrasonics_faq/ultrasonics_physics.pdf
http://www.eecs.berkeley.edu/~hu/PUBLICATIONS/Hu_papers/Hu_JNL/HuC_JNL_114.pdf
Lead zirconium titanate is an intermetallic inorganic compound with the chemical formula Pb[ZrxTi1-x]O3 (0≤x≤1). Also called PZT, it is a ceramic perovskite material that shows a marked piezoelectric effect, which finds practical applications in the area of electroceramics. It is a white solid that is insoluble in all solvents.
Varieties of PZTs
One of the commonly studied chemical composition is PbZr0.52Ti0.48O3. The increased piezoelectric response and poling efficiency near to x = 0.52 is due to the increased number of allowable domain states at the MPB. At this boundary, the 6 possible domain states from the tetragonal phase <100> and the 8 possible domain states from the rhombohedral phase <111> are equally favorable energetically, thereby allowing a maximum 14 possible domain states.Like structurally similar lead scandium tantalate and barium strontium titanate, PZT can be used for manufacture of uncooled staring array infrared imaging sensors for thermographic cameras. Both thin film (usually obtained by chemical vapor deposition) and bulk structures are used. The formula of the material used usually approaches Pb1.1(Zr0.3Ti0.7)O3 (called PZT 30/70). Its properties may be modified by doping it with lanthanum, resulting in lanthanum-doped lead zirconium titanate (PLZT, also called lead lanthanum zirconium titanate), with formula Pb0.83La0.17(Zr0.3Ti0.7)0.9575O3 (PLZT 17/30/70).[6]
https://en.wikipedia.org/wiki/Lead_zirconate_titanate
PHYSICS QUESTIONS
Q. Why is there piezoelectricity?
A. Because some atomic lattice structures have as an essential unit (or "cell") a cubic or rhomboid cage made of atoms, and this cage holds a single semi-mobile ion which has several stable quantum position states inside the cell. The ion's post ion state can be caused to shift by either deforming the cage (applied strain) or by applying and electric field. The coupling between the central ion and the cage provides the basis for transformation of mechanical strain to internal electric field shifts and vice versa.
Q. What is electric field?
A. An electric field is always associated with the presence of electric charges. It fills the space around the charge and is the mechanism of interaction between charges. A test particle with small known charge (Q) placed near a charge concentration will experience an accelerating force (F) due to the field. The value of the electric field (E) at that location is the ratio F/Q (a vector).
Q. What is strain?
A. When a solid object like a rod of length (L) is stretched to a new length (L + delta L), the strain in the rod is defined as the ratio (delta L)/(L). This is a dimensionless measure of stretching or compression often stated as "inches per inch", "millimeters per meter", or "microns per meter (microstrain)" for convenience of visualization.
Q. What is elastic modulus (or Young's modulus) ?
A. A material property of all elastic solids, Young's modulus (Y) is used to describe "stiffness" of materials. When rod or plate of cross section (A) and length (L) is pulled with force (F) resulting in an elongation (delta L), the Young's modulus can be computed as follows: Y = (L/A)*(F/deltaF)
In piezo applications Y is frequently used to estimate the equivalent spring constant of a rod or a plate of material (i.e. that quantity (F/deltaF) that is in contact with a piezo actuator).
Q. What is tensile strength?
A. Tensile strength is the stress (measured in Newtons/m^2 or psi) at which a sample of solid material will break from tension.
Q. What is poling/depoling in piezoceramic materials?
A. The piezoelectric property of ceramics does not arise simply from its chemical composition. In addition to having the proper formulation the piezoceramics must be subjected to a high electric field for a short period of time to force the randomly oriented micro-dipoles into alignment. This alignment by application of high voltage is called "poling". At a later time, if an electric field is applied in the opposite direction it exerts a "dislodging stress" on the micro-dipoles. Low level
applied fields result in no permanent change in the polarization (it bounces back upon removal). Medium fields result in partial degradation of the polarization (with partial loss of properties). High applied fields result in repolarization in the opposite direction.
Q. What is damping?
A. 'Damping' is the term used for the general tendency of vibrating materials or structures to lose some elastic energy to
internal heating or external friction.
Q. Can piezoceramic actuators be used at cryogenic temperatures?
A. Yes. All piezo actuators continue to function right on down to zero degrees Kelvin. This may seem counter-intuitive at first; however, you must remember that the basis for the piezoelectric effect is inter-atomic electric fields, and electric fields are not affected by temperature at all. Quantitatively, the piezo coupling of most common piezoceramics does decrease as temperature drops. At liquid helium temperatures, the motion of most materials drops to about half that measured at room temperature.
Q. What is the pyroelectric effect?
A. The tendency of some materials to exhibit a change in internal electrical polarization state in response to a change in temperature. If the materials are equipped with electrodes on two surfaces, a voltage will arise between the electrodes in response to temperature shifts.
http://mastersonics.com/documents/mmm_basics/general_info/ultrasonics_faq/ultrasonics_physics.pdf
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