1) You first do you ferroelectric P-E hysteresis loop measurements, and then do the poling treatment. Because you are working on a new composition, and for such a composition you don't know what is the polarisation and the coercive field. Hence first do the P-E hysteresis loop measurements.
2) Poling treatment
Poling means applying a DC voltage across your pellets. The appropriate DC voltage should be at least 2 to 3 times the Ec values (coercivie field), which can be determined by doing the P-E hysteresis loop measurements.
So once you know the coercive field, and the thickness of your pellet, then you can determine the exact DC voltage that is required to be applied on your pellet for effective poling.
You must take care, because let us say you figure out that you need a DC voltage of more than 1 KV, or 2 KV is to be applied across your sample, then you should keep your pellet in oil and then apply the field. Otherwise there will be sparking near the edges due to fringing fields, and short the sample, and blow the fuse of your DC power supply.
3) Once you have poled your sample, you need worry about any time. The sample will remain in the poled state, provided it is not a leaky sample, which means it has a high enough resistivity. Ferroelectric samples will remain poled unless, they get depoled, via reapeated heating and cooling through their transition temperature.
K. Sreenivas
1) You first do you ferroelectric P-E hysteresis loop measurements, and then do the poling treatment. Because you are working on a new composition, and for such a composition you don't know what is the polarisation and the coercive field. Hence first do the P-E hysteresis loop measurements.
2) Poling treatment
Poling means applying a DC voltage across your pellets. The appropriate DC voltage should be at least 2 to 3 times the Ec values (coercivie field), which can be determined by doing the P-E hysteresis loop measurements.
So once you know the coercive field, and the thickness of your pellet, then you can determine the exact DC voltage that is required to be applied on your pellet for effective poling.
You must take care, because let us say you figure out that you need a DC voltage of more than 1 KV, or 2 KV is to be applied across your sample, then you should keep your pellet in oil and then apply the field. Otherwise there will be sparking near the edges due to fringing fields, and short the sample, and blow the fuse of your DC power supply.
3) Once you have poled your sample, you need worry about any time. The sample will remain in the poled state, provided it is not a leaky sample, which means it has a high enough resistivity. Ferroelectric samples will remain poled unless, they get depoled, via reapeated heating and cooling through their transition temperature.
K. Sreenivas
Thanks, Prof. K. Sreenivas..
In some samples, poling at suitable temperature also results in better ferroelectric and piezoelectric properties.
Dear Sanada,
it is important to consider also the material you are going to use for your experiments. Some of them required pre-process before to be poled (e.g. stretching procedure).
Best regards
Dear Sananda Das
Piezoelectric properties of electroceramics can be improved or induced by optimizing the poling parameters. Ceramics should be poled more than their coercive filed.
1. Measure the saturated P-E loop.
2. Calculate the Ec from P-E loop.
3. Pole the sample more than Ec. Poling field will be same for the all samples but poling voltage vary with sample thickness.
4. After poling do the d33 measurement to confirm the process.
Please check the following articles
https://www.researchgate.net/publication/273446569_Poling_electric_field_dependent_domain_switching_and_piezoelectric_properties_of_mechanically_activated_Pb092La008Zr060Ti040O3_ceramics
Article Optimization of poling parameters of mechanically processed ...
Regards
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