Magnetoelectric Response User Manual
Contents
1. Knowing the Value of H is a Challenge e The magnetic field at within or through the sample under test is dependent on o Helmholtz Coil geometry and its coil current o Sample position o Sample orientation o Sample geometry e The Vision program includes a geometry term to correct for geometry variances if the sample is not placed in the center of the Helmholtz coil e A calibrated ammeter can be placed in the current loop in series with the current sensor The Hall Effect sensor can be placed in the center of the Helmholtz coil in place of the sample All four can be calibrated against each other using the Magnetoelectric Calibration Task e Radiant considers the most absolute reference to be the current reported by a NIST traceable ammeter times the calibration coefficient of the Helmholtz coil The current sensor and Hall Effect sensor should be calibrated against that reference Radiant Technologies Inc Nullified Parasitics Since the tester steps and waits at each The virtual ground input of the point the magnetic field is not changing polarization tester maintains zero when each charge value is captured volts on one side of the sample ee ee E EE S A E E E a S O E E E E E E Twisted Pair Coax be seeeeeucie Self Capacitance Capacitance a SRO tatty The external test circuit adds no parasitics to the test Only the input parasitics of the tester must be characterize2. um I 1 g m pon ps current o A i source i Set Sample Info i i Start with Last Amp Value X I amplifier a Set SENSOR 1 Sensor Enabled Calculated Field by Current Measured at Sensor 1 Auto Amplification 7 eee eres I Set SENSOR 2 Sensor 2 Enabled Magnetic Field Measured at Sensor 2 Read Data From Vision File Ip ae SS as ee eS ee 1 r M Smooth Data Before Pr and Vc Sample Area in cm To output results in units of i I l picocoulombs instead of polarization Help l set this value to 1x10 p EP TE E EE E ATR gt a FERROELECTRIC M Response Version 4 9 4 Radiant Technologies Inc 2011 2 07 13 DIANT TEST SYSTEMS Radiant Technologies Inc Sensor Setup Menus e The Output BNC of the Radiant Current Sensor should be connected to SENSOR on the rear panel of the tester e Click on the SENSOR 1 button of the MER Task menu Check this box to turn on i 1 l SENSORI Scale factor E wesaried L 2 1 willbe x es os 1 Mi at I correctly is SENSOR 1 Current Detector Configuration g l 1 sL selected by ag Use Current Detector E a Fi i the menu i a Offset cee E To capture 1 SENSOR 1 0 x 9 3125 Current in Amps I sensor l I l i offset _ a gt Capture Offset vI RCSI eee oan 2 2 ee ipa OO oe 1 click eee Select Current i button and Sensor Type follow S R 1 direction
3. 08 Poly True Charge w y 0 001x 0 0032x 0 0084 R 0 9767 0 6 0 5 0 4 Nn 2 2 5 9 2 0 2 H field Oe Zero Bias Magneto electric response with 2 order polynomial fit e Typical charge response for composite magnetoelectric sample e Measurement scale is 1 picocoulomb The sample was fabricated by Mr Su Chul Yang and Mr Shashaank Gupta of Virginia Tech s Center for Energy Harvesting Materials and Systems CEHMS It consisted of KNNLS NZF cut into disks with an area of 0 785 cm and a thickness of 0 05 cm The disks were bonded to a nickel foil The oy of the sample was measured by Virginia Tech using the traditional voltage technique and a lock in amplifier At a field of 25 Oersted the sample generated an ay of 1 2 mV cm Oe Radiant Technologies Inc Ferroelectric Properties vs H field e To measure the ferroelectric properties of the sample in a magnetic field the test configuration must be changed to that below e Sample is connected between DRIVE and RETURN as is standard for electrical measurements e An PC DAC is connected between the tester and the current amplifier of the magnetic coil to allow Vision to set DC magnetic fields across the sample Field Coil e Use the DC Magnetic Field Task from the Vision Library to set the magnetic field in a Test Definition prior to making electrical meee measurements host Precision
4. Magnetoelectric Response User Manual Joe T Evans Scott Chapman Jr Radiant Technologies Inc May 20 2013 Radiant Technologies Inc Summary Magnetoelectric effect Test Configuration Current Loop Sample Loop Sensor Loop Test Execution Radiant Technologies Inc Magnetoelectric Effect V Voltage Measurement e During the traditional voltage measurement technique charge generated in the sample by the magnetic field produces a voltage across the capacitance of the sample e Radiant testers measure charge so we suggested the following test Q Charge Measurement H AP Q X AH Radiant Technologies Inc Test Procedure e The charge based magneto electric measurement is an exact analog to the traditional polarization hysteresis measurement e The tester drives H and measures P e gq oP dH Electrically Generated Polarization volts Magnetically Generated Polarization Radiant Technologies Inc Magnetoelectric Test Configuration 1 The tester DRIVE output causes a current source to force current through the Helmholtz coil 2 The Helmholtz coil generates a magnetic field stimulating the sample 3 The RETURN input of Helmholtz Coil the Precision tester counts the electrons www P db SEEE F HET zaro produced by the sample under magnetic stimulation 4 The Current Sensor determines the current through the Helmholtz co
5. Tester Radiant Technologies Inc Magnetic Coils e This application note always refers to a Helmholtz coil as part of the test configuration e Any magnetic coil may be substituted for the Lakeshore MH 6 Helmholtz coil provided with the magnetoelectric measurement package from Radiant e The only requirement is that the current amplifier for the new coil accept a voltage control input e Single coils may be used in place of Helmholtz coils but the user must perform the mathematical calculations to determine the magnetic field at the sample and then adjust the Geometry Coefficient to allow Vision to convert the assigned magnetic field at the sample to the proper coil current during the test e Be aware of the cooling requirements and current limits of any coil connected to a Radiant tester Radiant Technologies Inc
6. d and subtracted t is roughly equal to 0 2pC 25 Oe ME voltage source PN seeeecoss i The sample is grounded z on the other side Radiant Technologies Inc Magnetoelectric Response Task e The charge produced by the sample in response to a magnetic field can be measured with the Magnetoelectric Response Task MER I 5 1 Test Period l in i 4 I bage k 7 i milliseconds Magneto Electric Response QuikLook Setup Veo vecsoeseeeee 4 Magneto Electric Response QuikLook Measurement Setup QuikLook Plot Setup ye M E Response Task Name DC Field Max Field Oe or G Field Period ms l IO Test TEA El Apply DC Field 45 lt x 7000 I u gt I pe Drive Profile Type Current Amps Field Oe or G Ratio _ Field Offset Oe or G Waveform r a lt 2 Pe a fe bees 1 1 1 0 0373 0 SS Standard Monopolz rf Curent Amplifier Volts Amp V Preset Toop _ Bipolar 1 75 Pre Loop Delay ms J 2222 2 22 J All Zeroes Geometry Coefficient Feld Field 0 x G C 1000 Peak E 7 1 000 I poore ER 7745n sn 1 Magnetic 1 DC Field setting Max Applied Volts Max Applied Curent Field 1 1 i 1 100 2 94 1 68 H k during test during Requires PC DAC and 1 Sample Area cm2 Sample Thickness um T 3 1 a ate i second magnetic coil A 0 0001 03 osi E Sensor _ 777 1 1 Set Sample Info Setting
7. es not matter but reverses the sign of the charge response 3 One side of the sample is grounded by connecting the short coaxial SMA pigtail included with the ME S Lo e i or the shield package side of the Sample RETURN Loop coaxial cable SENSOR2 SENSOR1 DRIVE RETURN Precision Tester Radiant Technologies Inc Sensor Loop e The sensor loop can have a current sensor in line with the current loop a Hall Effect sensor both or neither Hall Effect Sensor Helmholt e The Current Sensor is always O OO TP 7 on Sensorl E Current Sensor Current e The Hall Effect Loop sensor is always on Sensor 2 sail oop Hanes a T SENSOR2 SENSOR1 DRIVE RETURN Precision Tester Radiant Technologies Inc Current Sensor The Current Sensor has two BNC connectors on its rear panel Do not use SYNC 18V AC Power Helmholtz Coil Current Sensor SENSOR2 SENSOR 1 DRIVE RETURN Precision Tester Radiant Technologies Inc Current Sensor e There are two versions of the Radiant Current Sensor gt The RCSi uses a differential amplifier to measure the current flow between the red and black banana plugs This system is very accurate and holds off of 250 volts gt The RCSh uses a Hall Effect sensor to measure the current flow between the red and black banana plugs It can hold off 1500 volts It will be much less sensitive to large external magne
8. il from which the magnetic field can be SENSOR 1 DRIVE RETURN calculated Precision Multiferroic Radiant Technologies Inc Helmholtz Coil e A Helmholtz coil consists of two co axial identical wire coils separated by the radius of the coils e The magnetic field around the volume occupied by the Helmholtz coil is complex but is easy to calculate in the exact center of the structure e The equation describing the magnetic field at the center point of the axis between the two coils is B 0 716u x N R where N the number of turns of each coil I the current through the coils R the radius of the coils and the separation between the coils Radiant Technologies Inc Three Loops e The test configuration for magnetoelectric testing consists of three loops Hall Effect Sensor Helmholtz Coil Current Sensor Loop Loop SENSOR2 SENSOR 1 DRIVE RETURN Precision Tester Radiant Technologies Inc e The current loop consists of gt A voltage to current converter called a current source gt A current sensor gt A Heimholizcoi In normal Kepco operation all of three of these switches must be pointing to the right Radiant Technologies Inc Sample Loop 1 When measuring the magnetoelectric response of the sample one side is connected to ground while the other is connected to the tester RETURN input 2 The orientation of connection do
9. kLook Plot Setup Plot Title 60 Characters Max co eee oe ee eee 1 1 I 1 Graph 1 oo i p a d Plot X Axis Label 60 Characters Max labels 1 Ueda ead Feo o User Self Prompt 60 Characters Max Parameterto Append to Prompt _ Plot Subtitle 60 Characters Max Plot Y Axis Label 60 Characters Max Polarization Cem Data Label 32 Characters Max ME Response Data Plot Fiter a Calculated Field Oe By Applied Volts Amp Voltage Gain Calculated Field Oe By Measured Current Sensor 1 Centering Area Measured Field Oe Sensor 2 dQ uC dH Oe Vs Field Oe ico o S aS SS 2 Capacitor ID Normalized dP uC cm2 dH Oe Vs Field Oe I S jl t i Die Column A Subsamole D Polarization Vs Time x i elec 1 Die Row amin aha Centered Vs Time aak 1 lotti i Drive Channel i SEAE dQ uC dH Oe Vs Time qJ44_ 1 plotting Drive Port v 7 V Display Tabbed Normalized dP uC cm2 dH Oe Vs Time t 1 1 Charge uC Vs Field Oe i ormat Plot Sensor 1 If Enabled e P e E E od BS ae I Centered Charge uC Vs Field Oe eee ere 7 Ph K I I Centered Charge uC Vs Time ia Senar AEE l Select source of I Polarization Vs Field w Curve Fit i Polarization Vs Time w Curve Fit Comments 511 Characters Mx Axis values Radiant Technologies Inc Magnetoelectric Response Task Average Sample Inducted Charge True Charge
10. s Hep Lox came Licence m RADIANT a TEST OYSTERS TECHNOLOGIES INC Radiant Technologies Inc Sensor Setup Menus e The custom output cable of the Gauss Meter should be connected to SENSOR2 on the rear panel of the tester e Click on the SENSOR 2 button of the MER Task menu Check this The Hall Effect Sensor offset can be measured withthe sensor 1 box to turn shielded to zero or from the front panel display of its control unit l Leave setat i i i ee ee ae fo a ie f Zero SENSOR2 r A a a Lstecsoneseeass S A Sensor Configuration a N t gt a gt r Sa 1 a N Ya J te cones oe V Sensor Enable aoa t oo Sensor Scale Sensor Offset Sensor Impedance Sensor Label 12 Character Max 1 z o y 0 Mar Field ie I ee Nee ea S Cr a a a ia tarsi set i i Sensor Data Set units label Sensed Voltage input Impedance Sensor Impedance Input Impedance Scale Offset Wg eA ytd ok epee eevee Hall Effect Sensor scale factors will be labeled on the custom cable connecting the Hall Effect Sensor to the tester Radiant Technologies Inc Magnetoelectric Response Task e The second page of the MER Task menu contains plotting information Test Period s s milliseconds r Magneto Electric Response QuikLook Setup I I 4 In I I I Magneto Electric Response QuikLook Measurement Setup Qui
11. s 1 _ Start with Last Amp Value 7 L gt Sensor Enabled Calculated Field by Curent Measured at Sensor 1 Ato Anpification BE Set SENSOR 2 Sensor 2 Enabled Magnetic Field Measured at Sensor 2 Read Data From Vision File E Smooth Data Before Pr and Vc FERROELECTRIC M Response Version 4 9 4 Radiant Technologies Inc 2011 2 07 13 RADIANT TEST SYSTEMS Radiant Technologies Inc Magnetoelectric Response Task H m of ee I Magneto Electric Response QuikLook Setup sl C onversion Magneto Electric Response QuikLook Measurement Setup QuikLook Plot Setup i i ratio of i I M Response Task Name DC Field Max Field Oe or G Field Period ms zj L 4 current to P i e m I E Apply DC Field 45 ed 1000 field for Drive Profile Type Curent Amps Field Oe or G Ratia Field Offset Oe or G Helmholtz i Pon ea EEE aR 0373 477 Po il i col I Geometry us a Current Amplifier Volts Amp V Preset Loop Aare SETE i x Coefficient me k ma Pre Loop Delay ms I S E Double Bipolar T L a T i AiZemes DE Remin Geometry Coefficient Field x Field 0 xG CJ _ 1000 Conversion 7000 gt 4 ratioof I Applied Volts Max Applied Curent i v olt s to pus Seether Sess 100 _L gt 2394 1 68 1 Information only Peseta sslteo l za amps for i l aaea naa E Sample Area cm2 Sample Thickness
12. tic fields from large Helmholtz or field coils e With either current sensor Vision multiplies the current value reported by the sensor times the conversion ratio of the magnetic coil to calculate the magnetic field at the center of the coil Radiant Technologies Inc Lakeshore 425 Gauss Meter e A Hall Effect gauss meter may be inserted into the volume next to the sample to measure the magnetic field directly e The Hall Effect Hall Effect Sensor Effect Sensor sensor is always Helmholtz Coil on Sensor 2 HP iit 4 field gt e The Hall Effect Current Sensor Current Sensor Sensor sensor may not Current Loop be used at the same time as the Sensor Loop Radiant A EA A Magnetoelectric H H Fi H Sample Fixture SENSOR2 SENSOR 1 DRIVE RETURN USB to host Precision Tester Radiant Technologies Inc Hall Effect vs Current Sensor e The Hall Effect sensor can be 0 5 accurate and directly measures the magnetic field but is sensitive to misalignment in three dimensions e The current sensor can capture the current within 2 and is used with the coil geometry to calculate the magnetic field in the Helmholtz volume e If neither is available Vision will estimate the applied magnetic field using the volts to amps conversion ratio of the current source the amps to field conversion ratio of the Helmholtz coil Tester Hall Effect Sensor Radiant Technologies Inc
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