CN102323495A - Device and method for measuring polarization reversal curve of ferroelectric material - Google Patents
Device and method for measuring polarization reversal curve of ferroelectric material Download PDFInfo
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- CN102323495A CN102323495A CN201110139829A CN201110139829A CN102323495A CN 102323495 A CN102323495 A CN 102323495A CN 201110139829 A CN201110139829 A CN 201110139829A CN 201110139829 A CN201110139829 A CN 201110139829A CN 102323495 A CN102323495 A CN 102323495A
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Abstract
The invention discloses a device and method for measuring a polarization reversal curve of a ferroelectric material in the technical field of testing ferroelectric materials and piezoelectric materials. The device comprises a test signal output part, a polarization reversal curve test part and an equipment control and data acquisition processing part. High-voltage square wave pulse is controlled to be applied to a serial circuit consisting of a sample to be measured and a standard capacitor through switching on or off a high-voltage switch, voltage signals at two ends of the standard capacitor are acquired and subjected to conversion processing through computer software to obtain the polarization reversal curve. The device is subjected to overvoltage protection on a test apparatus by adopting a virtual ground lead technology. The invention solves the problem that no apparatus for testing the polarization reversal curve exists in the field of research of the ferroelectric materials and the piezoelectric materials in China. The device has the characteristics of stable performance and high test efficiency, and has the advantages of better configuration and expansibility, simple structure, easiness in assembly, convenience and practicability and high safety.
Description
Technical field
The invention belongs to ferroelectric and the piezoelectric technical field of measurement and test, particularly a kind of device and method of measuring ferroelectric material polarization reversal curve.
Background technology
Since the piezoelectricity ferro material came to light, along with the continuous progress to its research, the range of application of this type of material is expansion gradually also.The application of ferroelectric ceramic material has at present related to across a plurality of fields of science and techniques of defence to daily life.Therefore, the importance of piezoelectricity ferro investigation of materials in materialogy also increases thereupon.In order to improve material property to realize application more widely, we need start with from the micromechanism of ferroelectric material and the mechanism of production of various macro properties.As the basis that ferroelectric material characteristic lag loop produces, the polarization reversal of material internal domain structure is effective breach of research ferroelectric material Related Mechanism, and the polarization reversal curve polarization intensity-time curve of sample is then significant to this research.Through investigating the polarization reversal delay phenomenon, we can also study ferroelectric material fatigue failure mechanism, thereby promote the raising of reliability of material.
When the electric property of research ferroelectric material, generally adopt the Sawyer-Tower circuit at present, be about to testing sample and connect with standard capacitance, wherein the standard capacitance value is much larger than the testing sample capacitance.Can obtain the electrical quantities such as polarization intensity of testing sample through the voltage at measurement standard electric capacity two ends, and draw various relation curves thus.But sample breakdown can produce instantaneous pressure in the test process, possibly cause damage to testing tool.
The at present domestic test macro that does not still have test polarization reverse curve.
Summary of the invention
The objective of the invention is research needs, disclose a kind of device and method of measuring ferroelectric material polarization reversal curve to ferroelectric material performance mechanism described in the background technology.
Said device comprises test signal output 1, polarization reversal curved measurement part 2 and device control and data acquisition process part 3; Wherein:
The structure of said test signal output 1 is following: dc high-voltage source 101 is connected with buffer capacitor 104 through high-voltage switch gear 102; Signal generator 103 is connected with capture card 303, oscillograph 302, computing machine 301 and high-voltage switch gear 102 respectively;
The structure of said polarization reversal curved measurement part 2 is following: testing sample 201 links to each other with relay group 203; The one termination testing sample 201 of current-limiting resistance 205 and the common node of relay group 203; The common node of another termination buffer capacitor 104 and high-voltage switch gear 102; Standard capacitance 202 is parallelly connected with virtual ground holding circuit 204 simultaneously; The latter links to each other with capture card 303, oscillograph 302, and standard capacitance 202, testing sample 201 and virtual ground holding circuit 204 constitute improved Sawyer-Tower circuit;
Said device control is following with the structure of data acquisition process part 3: capture card 303 links to each other with signal generator 103, standard capacitance 202, computing machine 301 and oscillograph 302 respectively, and oscillograph 302 links to each other with standard capacitance 202 and computing machine 301 respectively.
The structure of said virtual ground holding circuit 204 is following: the negative input end of operational amplifier OP links to each other with output terminal; Its positive input terminal ground connection, its output termination first resistance R 1, the second resistance R 2 links to each other with the negative input end of operational amplifier OP; One termination, first resistance R 1 of capacitor C 1; Other end ground connection, the capacitor C 1 and first resistance R 1 constitute RC wave filter, parallelly connected Transient Suppression Diode D between the positive and negative input end of operational amplifier OP.
Said operational amplifier OP is the AD549 operational amplifier.
The capacitance of said standard capacitance 202 is 5 μ F, and withstand voltage is 2000V.
A kind of method of measuring ferroelectric material polarization reversal curve is characterized in that, may further comprise the steps:
Step 1: dc high-voltage source 101 provides the DC high voltage signal, and this signal is by high-voltage switch gear 102 blocking-up;
Step 2: signal generator 103 produces the 102 closed set times of square-wave pulse control high-voltage switch gear; High direct voltage signal through high-voltage switch gear 102 is behind buffer capacitor 104; Put on testing sample 201 and standard capacitance 202 two ends, testing sample 201 is polarized;
Step 3: pilot relay group 203 makes repeating step one and two behind 201 liang of umpolungs of testing sample; Change signal generator 103 and produce the square-wave pulse width of fixed width and the data collection rate of capture card 303; The square-wave pulse signal of the generation of oscillograph 302 monitor signal generators 103 and the voltage signal of standard capacitance 202, capture card 303 are gathered the control signal data of the voltage data and the corresponding signal generator 103 of standard capacitance 202 under the testing sample 201 different reversing time sections through oscillograph 302;
Step 4: the voltage data of standard capacitance 202 and the control signal data of signal generator 103 are input in the computing machine 301, through the image and the data file of computing output polarization reverse curve.
The square-wave pulse width that said signal generator 103 produces is 0.001s-100s.
The Measuring Time cycle of said polarization reversal curve is 600s-1000s.
The invention has the beneficial effects as follows:
1) adopt the test circuit of forming by testing sample and normal linearity capacitances in series the polarization reversal curve to be measured the method simple, intuitive.
2) applying through realizing in the time that the high-voltage switch gear of make-break operation carries out at nanosecond order of high direct voltage pulse, test result is accurate.
3) adopt capture card in oscillograph supervisory circuit signal, data to be gathered, realized the real-time measurement under the short test duration.
4) voltage limit after the sample breakdown realizes through the virtual ground circuit, has prevented the influence of big DC voltage to testing tools such as oscillographs like this, has played protective effect.
Description of drawings
Fig. 1: the structured flowchart of measurement mechanism;
Fig. 2: virtual ground holding circuit synoptic diagram
Fig. 3: device control and data acquisition process process synoptic diagram;
Fig. 4: the ferroelectric ceramics sample polarization reverse curve in the embodiment of the invention 1.
Fig. 5: the sample of the embodiment of the invention 2 is through the polarization reversal curve comparison diagram behind the fatigue experiment of different number of times.
Reference numeral: 1-test signal output 2-polarization reversal curved measurement part 3-device control and data acquisition process
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment is elaborated.Should be emphasized that following explanation only is exemplary, but not in order to limit range of application of the present invention.
The present invention provides a kind of method of testing and proving installation of measuring ferroelectric material polarization reversal curve.The control system source program of this device uses the programming of Labview platform, through VISA remote control signal generator (Agilent 33220A), integrates capture card 303 programs.
Be illustrated in figure 1 as the proving installation of measuring ferroelectric material polarization reversal curve, comprise test signal output 1, polarization reversal curved measurement part 2 and device control and data acquisition process part 3.Wherein:
The structure of said test signal output 1 is following: dc high-voltage source 101 is connected with buffer capacitor 104 through high-voltage switch gear 102; Signal generator 103 is connected with capture card 303, oscillograph 302, computing machine 301 and high-voltage switch gear 102 respectively;
The structure of said polarization reversal curved measurement part 2 is following: testing sample 201 links to each other with relay group 203; The one termination testing sample 201 of current-limiting resistance 205 and the common node of relay group 203; The common node of another termination buffer capacitor 104 and high-voltage switch gear 102; Standard capacitance 202 is parallelly connected with virtual ground holding circuit 204 simultaneously; The latter links to each other with capture card 303, oscillograph 302, and standard capacitance 202, testing sample 201 and virtual ground holding circuit 204 constitute improved Sawyer-Tower circuit;
Said device control is following with the structure of data acquisition process part 3: capture card 303 links to each other with signal generator 103, standard capacitance 202, computing machine 301 and oscillograph 302 respectively, and oscillograph 302 links to each other with standard capacitance 202 and computing machine 301 respectively.
The capacitance of said standard capacitance 202 is 5 μ F, and withstand voltage is 2000V.
As shown in Figure 2, the structure of said virtual ground holding circuit 204 is following: the negative input end of operational amplifier OP links to each other with output terminal, its positive input terminal ground connection; Its output termination first resistance R 1; Second resistance R 2 links to each other with the negative input end of operational amplifier OP, a termination first resistance R 1 of capacitor C 1, other end ground connection; The capacitor C 1 and first resistance R 1 constitute RC wave filter, parallelly connected Transient Suppression Diode D between the positive and negative input end of operational amplifier OP.
Said operational amplifier OP is the AD549 operational amplifier.
The measuring process of polarization reversal curve is following: dc high-voltage source 101 provides the DC high voltage signal, and this signal is by high-voltage switch gear 102 blocking-up, and high-voltage switch gear 102 can be accomplished make-break operation in the time at nanosecond order; Signal generator 103 produces the 102 closed set times of square-wave pulse control high-voltage switch gear; The make-and-break time of guaranteeing high-voltage switch gear 102 is accurate; High direct voltage signal through high-voltage switch gear 102 is behind buffer capacitor 104; Put on testing sample 201 and standard capacitance 202 two ends, testing sample 201 is polarized, buffer capacitor 104 can effectively be eliminated the signal fluctuation that switch on and off causes; Avoid the instrument infringement and ensure that test result is accurate, current-limiting resistance 205 is the electric current of restricted passage testing sample effectively.Pilot relay group 203 makes repeating step one and two behind 201 liang of umpolungs of testing sample, changes signal generator 103 and produces the square-wave pulse width of fixed widths and the data collection rate of capture card 303;
As shown in Figure 3,201 carried charges of testing sample equate with the carried charge of standard capacitance 202, i.e. Q
X=Q
0And, obtain C by Q=CV
xV
x=C
0V
0, C wherein
0And V
0Be respectively the capacitance and the voltage thereof of standard capacitance 202, C
xAnd V
xBe respectively the capacitance and the voltage thereof of testing sample 201.Because C
0Value is much larger than C
x, the historical facts or anecdotes border puts on the magnitude of voltage at standard capacitance 202 two ends much smaller than testing sample 201 voltage, so that can measure collection by oscillograph 302, and testing sample 201 voltage also can be similar to and think and equal the high pressure that stimulus part produces.According to C
x=C
0V
0/ V
x, therefore pass through capture card 303 with V
0Signals collecting is to computing machine 301 and read numerical value, just can calculate the real-time capacitance values of testing sample 201 and and then by P
s=Q
X/ A and Q
X=C
xV
x=C
0V
0(P wherein
sBe sample polarization intensity, Q
XBe sample institute carried charge, A is the sample electrode area) obtain the polarization intensity of testing sample 201.
According to the electrology characteristic of operational amplifier, its negative terminal voltage equates that with positive terminal voltage when positive ending grounding, the negative terminal electromotive force equates with earth potential, promptly so-called virtual ground.Because virtual ground holding circuit 204 is parallelly connected with standard capacitance 202, so input end signal is the voltage signal of standard capacitance 202.Behind the RC filter filtering, measure its electromotive force through oscillograph 302 at collection terminal and can obtain standard capacitance 202 voltage.When sample breakdown; When high pressure is about to through operational amplifier OP; The Transient Suppression Diode D of parallel connection will play the pressure limiting effect; Make reality be no more than the rating number of Transient Suppression Diode D, thereby play the effect of protection operational amplifier OP and follow-up test instrument through the voltage of operational amplifier OP.
The square-wave pulse width that said signal generator 103 produces is 0.001s-100s.Every the Measuring Time cycle according to the complete polarization reversal curve that the normal process test obtains is 600s-1000s.Sampling rate when requiring freely to set whole piece curve institute's segments and every section measurement according to experimental precision, the test degree of freedom is high.
Be two embodiment of the present invention below:
Embodiment 1:
Specimen is used PIC151 (PI Ceramics, Lederhose, Germany) ceramics sample, thickness of sample d=1mm, electrode area S=0.7854cm
2, the polarization reversal curve of this sample is as shown in Figure 4.
Embodiment 2:
Specimen is used PZT-5 ceramics sample, thickness of sample d=1mm, electrode area S=1.7663cm
2(calculate with ac frequency 50Hz, 1h, 2h, 5h and 15h be corresponding fatigue life cycle 1.8 * 10 respectively respectively sample to be carried out the fatigue experiment of 1h, 2h, 5h and 15h before the test
5, 3.6 * 10
5, 9 * 10
5With 2.7 * 10
5Inferior).Fig. 5 for this sample through the polarization reversal curve comparison diagram behind fatigue experiment of different number of times.
The above; Be merely the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, the technician who is familiar with the present technique field is in the technical scope that the present invention discloses; The variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.
Claims (7)
1. a device of measuring ferroelectric material polarization reversal curve is characterized in that, comprises test signal output (1), polarization reversal curved measurement part (2) and device control and data acquisition process part (3); Wherein:
The structure of said test signal output (1) is following: dc high-voltage source (101) is connected with buffer capacitor (104) through high-voltage switch gear (102); Signal generator (103) is connected with capture card (303), oscillograph (302), computing machine (301) and high-voltage switch gear (102) respectively;
The structure of said polarization reversal curved measurement part (2) is following: testing sample (201) links to each other with relay group (203); The one termination testing sample (201) of current-limiting resistance (205) and the common node of relay group (203); The common node of another termination buffer capacitor (104) and high-voltage switch gear (102); Standard capacitance (202) is parallelly connected with virtual ground holding circuit (204) simultaneously; The latter links to each other with capture card (303), oscillograph (302), and standard capacitance (202), testing sample (201) and virtual ground holding circuit (204) constitute improved Sawyer-Tower circuit;
Said device control is following with the structure of data acquisition process part (3): capture card (303) links to each other with signal generator (103), standard capacitance (202), computing machine (301) and oscillograph (302) respectively, and oscillograph (302) links to each other with standard capacitance (202) and computing machine (301) respectively.
2. a kind of device of measuring ferroelectric material polarization reversal curve according to claim 1; It is characterized in that the structure of said virtual ground holding circuit (204) is following: the negative input end of operational amplifier (OP) links to each other with output terminal, its positive input terminal ground connection; It exports termination first resistance (R1); Second resistance (R2) links to each other with the negative input end of operational amplifier (OP), a termination first resistance (R1) of electric capacity (C1), other end ground connection; Electric capacity (C1) and first resistance (R1) constitute RC wave filter, parallelly connected Transient Suppression Diode (D) between the positive and negative input end of operational amplifier (OP).
3. a kind of device of measuring ferroelectric material polarization reversal curve according to claim 2 is characterized in that said operational amplifier (OP) is the AD549 operational amplifier.
4. a kind of device of measuring ferroelectric material polarization reversal curve according to claim 1 is characterized in that, the capacitance of said standard capacitance (202) is 5 μ F, and withstand voltage is 2000V.
5. a method of measuring ferroelectric material polarization reversal curve is characterized in that, may further comprise the steps:
Step 1: dc high-voltage source (101) provides the DC high voltage signal, and this signal is blocked by high-voltage switch gear (102);
Step 2: signal generator (103) produces the closed set time of square-wave pulse control high-voltage switch gear (102); High direct voltage signal through high-voltage switch gear (102) is behind buffer capacitor (104); Put on testing sample (201) and standard capacitance (202) two ends, testing sample (201) is polarized;
Step 3: pilot relay group (203) makes repeating step one and two behind testing sample (201) two umpolungs; Change signal generator (103) and produce the square-wave pulse width of fixed width and the data collection rate of capture card (303); The voltage signal of the square-wave pulse signal of the generation of oscillograph (302) monitor signal generator (103) and standard capacitance (202), capture card (303) are gathered the control signal data of the voltage data and the corresponding signal generator (103) of standard capacitance (202) under the different reversing time sections of testing sample (201) through oscillograph (302);
Step 4: the voltage data of standard capacitance (202) and the control signal data of signal generator (103) are input in the computing machine (301), through the image and the data file of computing output polarization reverse curve.
6. a kind of method of measuring ferroelectric material polarization reversal curve according to claim 5 is characterized in that, the square-wave pulse width that said signal generator (103) produces is 0.001s-100s.
7. a kind of method of measuring ferroelectric material polarization reversal curve according to claim 5 is characterized in that the Measuring Time cycle of said polarization reversal curve is 600s-1000s.
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| CN 201110139829 CN102323495B (en) | 2011-05-27 | 2011-05-27 | Device and method for measuring polarization reversal curve of ferroelectric material |
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| CN 201110139829 CN102323495B (en) | 2011-05-27 | 2011-05-27 | Device and method for measuring polarization reversal curve of ferroelectric material |
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| CN102323495B CN102323495B (en) | 2013-07-03 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110244112A (en) * | 2019-06-19 | 2019-09-17 | 佛山科学技术学院 | A kind of measuring device and measuring method of time domain dielectric material polarization transient state |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1529183A (en) * | 2003-09-26 | 2004-09-15 | �Ϻ���ͨ��ѧ | Experiment apparatus for measuring ferro electric-hysteresis loop of ferroelectrics |
| CN2747587Y (en) * | 2004-07-26 | 2005-12-21 | 深圳华中科技大学研究院 | Ferroelectric material parameter tester |
| CN1888923A (en) * | 2006-07-17 | 2007-01-03 | 大连理工大学 | Ferroelectric film electric hysteresis loop measuring compensating method |
| CN101158712A (en) * | 2007-09-17 | 2008-04-09 | 西安交通大学 | Measurement mechanism and measurement method of ferroelectric materials electric hysteresis loop wire |
| CN101566660A (en) * | 2009-05-22 | 2009-10-28 | 清华大学 | Method and device for measuring electric hysteresis loop and strain loop of ferroelectric material simultaneously |
| CN101769969A (en) * | 2010-02-03 | 2010-07-07 | 清华大学 | Device and method for measuring piezoelectric constant loop and dielectric constant loop of ferroelectric material |
-
2011
- 2011-05-27 CN CN 201110139829 patent/CN102323495B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1529183A (en) * | 2003-09-26 | 2004-09-15 | �Ϻ���ͨ��ѧ | Experiment apparatus for measuring ferro electric-hysteresis loop of ferroelectrics |
| CN2747587Y (en) * | 2004-07-26 | 2005-12-21 | 深圳华中科技大学研究院 | Ferroelectric material parameter tester |
| CN1888923A (en) * | 2006-07-17 | 2007-01-03 | 大连理工大学 | Ferroelectric film electric hysteresis loop measuring compensating method |
| CN101158712A (en) * | 2007-09-17 | 2008-04-09 | 西安交通大学 | Measurement mechanism and measurement method of ferroelectric materials electric hysteresis loop wire |
| CN101566660A (en) * | 2009-05-22 | 2009-10-28 | 清华大学 | Method and device for measuring electric hysteresis loop and strain loop of ferroelectric material simultaneously |
| CN101769969A (en) * | 2010-02-03 | 2010-07-07 | 清华大学 | Device and method for measuring piezoelectric constant loop and dielectric constant loop of ferroelectric material |
Non-Patent Citations (2)
| Title |
|---|
| LUPASCU DORU C,ET AL: "Stretched exponential relaxation in perovskite ferroelectrics after cyclic loading", 《JOURNAL OF APPLIED PHYSICS》 * |
| ZHUKOV S,ET AL: "Effect of bipolar electric fatigue on polarization switching in lead-zirconate-titanate ceramics", 《JOURNAL OF APPLIED PHYSICS》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110244112A (en) * | 2019-06-19 | 2019-09-17 | 佛山科学技术学院 | A kind of measuring device and measuring method of time domain dielectric material polarization transient state |
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