Selected Applications attoAFM / CFM
PAGE 121 attoAFM / CFM
NV-Center Based Nanomagnetometry
Given its premier mechanical and thermal stability , the attoAFM / CFM is the ideal platform for nanoscale magnetic imaging employing an AFM tip with a diamond nanocrystal that contains a single nitrogen-vacancy ( NV ) center [ 1 ] - [ 4 ]. Local magnetic fields are subsequently evaluated by measuring the Zeeman shifts of the NV defect spin sublevels . In the particular case of NV-center magnetometry , an external microwave field is emitted and tuned in frequency such that local spin resonance occurs . This condition can subsequently be detected by a decrease in photoluminescence intensity of the NV-center , referred to as ODMR ( optically detected magnetic resonance ). Using a Lock-in and feedback loop technique allows to maintain spin resonance while rastering the sample , allowing to record a local magnetic field map with nanometer resolution .
In this example , magnetic imaging of a hard disk sample with random bit orientation was performed in the group of V . Jacques at LPQM , ENS-Cachan , France . [ 1 ]
Example 1 ( a , b ): Quantitative imaging using ODMR based method with NV-center scanned at d 1
= 250 nm above the sample . ( a ) Schematic of the measurement . ( b ) Quantitative magnetic field distribution recorded with the lockin technique ( 13 nm pixel size , 110 ms acquisition time per pixel ). The inset shows a line-cut taken along the dashed white line in the image . [ 1 ]
Example 2 ( c , d ): All-optical method with NV center closer to the sample surface . ( c ) Schematic of the measurement . ( d ) All optical photoluminescence image ( no microwave field applied ) recorded with the NV-scanning probe magnetometer in tapping mode ( 8 nm pixel size , 20 ms acquisition time per pixel ). Comparisons with simulations indicates that the tip surface distance is roughly d 2
= 30 nm . Fine white dotted lines are plotted along the direction of the hard disk tracks as a guide for the eye . [ 1 ]
References : [ 1 ] L . Rondin et al ., Appl . Phys . Lett . 100 , 153118 ( 2012 ) Related publications based on the attoAFM / CFM ( 2012-2016 )
[ 2 ] L . Thiel et al ., Nature Nanotechnology ( 2016 ), doi : 10.1038 / nnano . 2016.63 [ 3 ] Tetienne et al ., Science 344 , 1366 ( 2014 ) [ 4 ] J . -P. Tetienne et al ., Nature Communications 6 , 6733 ( 2015 ) [ 5 ] A . Dréau et al ., Phys . Rev . Lett . 113 , 137601 ( 2014 ) [ 6 ] A . Dréau et al ., Phys . Rev . Lett . 110 , 060502 ( 2013 ) [ 7 ] L . Rondin et al ., Nature communications 4 , 2279 ( 2013 ) [ 8 ] J . -P. Tetienne et al ., Phys . Rev . B 87 , 235436 ( 2013 ) [ 9 ] J . -P. Tetienne et al ., New J . Phys . 14 , 103033 ( 2012 ) [ 10 ] A . Dréau et al ., Phys . Rev . B 85 , 134107 ( 2012 ) [ 11 ] L . Rondin et al ., Appl . Phys . Lett . 100 , 153118 ( 2012 ) attoMICROSCOPY
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