Venkat Chandrasekhar
In: Review of Scientific Instruments, vol. 91, pp. 023705, 2020.
Abstract | Links | BibTeX | Tags: scanning probe, Tuning fork
@article{Chandrasekhar2020,
title = {A microchip microcontroller-based transducer controller for non-contact scanning probe microscopy with phase-locked loop, amplitude, and Q control},
author = {Venkat Chandrasekhar},
url = {https://aip.scitation.org/doi/10.1063/1.5131657},
doi = {10.1063/1.5131657},
year = {2020},
date = {2020-02-11},
journal = {Review of Scientific Instruments},
volume = {91},
pages = {023705},
abstract = {An inexpensive yet versatile transducer controller for non-contact scanning probe microscopy (SPM) based on a PIC32 microcontroller from Microchip Technology, Inc is described. In addition to feedback control using the amplitude or phase of the signal from the non-contact transducer, the controller includes a phase-locked loop for frequency-shift feedback, as well as fixed-amplitude, quality factor (Q) control, and self-excitation modes. Apart from the input amplifiers, output buffers, and the Q-control circuit, all other functions of the controller are instantiated in software on the microchip, enabling rapid changes in operating parameters if needed. The controller communicates with a host personal computer via a simple serial connection. The controller has been tested with a quartz tuning-fork transducer but can be used with any oscillating non-contact transducer.},
keywords = {scanning probe, Tuning fork},
pubstate = {published},
tppubtype = {article}
}
Patrick Krantz; Venkat Chandrasekhar
Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy Journal Article
In: Journal of Vacuum Science and Technology B, vol. 38, pp. 024004, 2020.
Abstract | Links | BibTeX | Tags: scanning probe, Tuning fork
@article{Krantz2020,
title = {Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy},
author = {Patrick Krantz and Venkat Chandrasekhar},
url = {https://avs.scitation.org/doi/10.1116/1.5132848},
doi = {10.1116/1.5132848},
year = {2020},
date = {2020-02-07},
journal = {Journal of Vacuum Science and Technology B},
volume = {38},
pages = {024004},
abstract = {Sharp tips are critical for obtaining high resolution images in scanning probe microscopy (SPM), particularly in samples with large variations in topography. For tuning-fork-based SPM, such tips are commonly obtained by electrochemical etching of metallic wires (e.g., tungsten). Electrochemical etching of metallic wires is the preferred means of preparing tips for scanning tunneling microscopy (STM), and techniques for obtaining sharp tips have been investigated extensively. However, the requirements for STM and tuning-fork-based SPM are different. In particular, the wires used in STM are typically 250−500 μm in diameter, while the wires used for tuning-fork-based SPM are usually an order of magnitude narrower in order to minimize loading of the tuning fork: 25−50μm and sometimes down to a few micrometers in diameter. Consequently, many of the recipes developed for etching thicker metallic wires for STM tips do not give optimal results for smaller diameter wires. The authors describe here a modification of the etching circuit of Ibe et al. that significantly improves the reproducibility and reliability of the etching process for thin wires, and discuss the parameters that affect the aspect ratio of produced tips.
},
keywords = {scanning probe, Tuning fork},
pubstate = {published},
tppubtype = {article}
}
Manan Mehta
Interplay between superconductivity and ferromagnetism at the LaAlO3/SrTiO3 interface PhD Thesis
2015.
Links | BibTeX | Tags: AMR, epitaxial, Kondo effect, Magnetic force microscopy, Magnetism, Mesoscopic quantum transport, scanning probe, Superconductivity, vortex dynamics
@phdthesis{Mehta2015,
title = {Interplay between superconductivity and ferromagnetism at the LaAlO3/SrTiO3 interface},
author = {Manan Mehta},
url = {http://www.nano.northwestern.edu/wp-content/uploads/2017/09/Manan_Mehta_PhD_Thesis.pdf},
year = {2015},
date = {2015-12-01},
keywords = {AMR, epitaxial, Kondo effect, Magnetic force microscopy, Magnetism, Mesoscopic quantum transport, scanning probe, Superconductivity, vortex dynamics},
pubstate = {published},
tppubtype = {phdthesis}
}
M. M. Mehta; Venkat Chandrasekhar
A hybrid analog-digital phase-locked loop for frequency mode non-contact scanning probe microscopy Journal Article
In: Review of Scientific Instruments, vol. 85, no. 1, pp. 013707, 2014.
Links | BibTeX | Tags: instrumentation, scanning probe
@article{mehta_hybrid_2014,
title = {A hybrid analog-digital phase-locked loop for frequency mode non-contact scanning probe microscopy},
author = { M. M. Mehta and Venkat Chandrasekhar},
url = {http://scitation.aip.org/content/aip/journal/rsi/85/1/10.1063/1.4862818},
year = {2014},
date = {2014-01-01},
urldate = {2015-10-23},
journal = {Review of Scientific Instruments},
volume = {85},
number = {1},
pages = {013707},
keywords = {instrumentation, scanning probe},
pubstate = {published},
tppubtype = {article}
}
Venkat Chandrasekhar; Manan Mehta
A real-time software simulator for scanning force microscopy Unpublished
2013.
Links | BibTeX | Tags: instrumentation, scanning probe
@unpublished{chandrasekhar_real-time_2013,
title = {A real-time software simulator for scanning force microscopy},
author = { Venkat Chandrasekhar and Manan Mehta},
url = {https://arxiv.org/abs/1307.7679},
year = {2013},
date = {2013-01-01},
urldate = {2016-12-28},
keywords = {instrumentation, scanning probe},
pubstate = {published},
tppubtype = {unpublished}
}
Venkat Chandrasekhar; M. M. Mehta
RTSPM: Real-time Linux control software for scanning probe microscopy Journal Article
In: Review of Scientific Instruments, vol. 84, no. 1, pp. 013705, 2013.
Links | BibTeX | Tags: instrumentation, scanning probe
@article{chandrasekhar_rtspm:_2013,
title = {RTSPM: Real-time Linux control software for scanning probe microscopy},
author = { Venkat Chandrasekhar and M. M. Mehta},
url = {http://scitation.aip.org/content/aip/journal/rsi/84/1/10.1063/1.4775717},
year = {2013},
date = {2013-01-01},
urldate = {2015-10-21},
journal = {Review of Scientific Instruments},
volume = {84},
number = {1},
pages = {013705},
keywords = {instrumentation, scanning probe},
pubstate = {published},
tppubtype = {article}
}
Goutam Sheet; Alexandra R. Cunliffe; Erik J. Offerman; Chad M. Folkman; Chang-Beom Eom; Venkat Chandrasekhar
dc and high frequency magnetic properties of nanopatterned CoFe2O4 arrays fabricated using sol-gel precursors Journal Article
In: Journal of Applied Physics, vol. 107, no. 10, pp. 104309, 2010, ISSN: 0021-8979, 1089-7550.
Links | BibTeX | Tags: Magnetism, microwave, perovskite, scanning probe
@article{sheet_dc_2010,
title = {dc and high frequency magnetic properties of nanopatterned CoFe2O4 arrays fabricated using sol-gel precursors},
author = { Goutam Sheet and Alexandra R. Cunliffe and Erik J. Offerman and Chad M. Folkman and Chang-Beom Eom and Venkat Chandrasekhar},
url = {http://aip.scitation.org/doi/10.1063/1.3393745},
doi = {10.1063/1.3393745},
issn = {0021-8979, 1089-7550},
year = {2010},
date = {2010-05-01},
urldate = {2016-12-28},
journal = {Journal of Applied Physics},
volume = {107},
number = {10},
pages = {104309},
keywords = {Magnetism, microwave, perovskite, scanning probe},
pubstate = {published},
tppubtype = {article}
}
Alexandra R. Cunliffe
2009.
Links | BibTeX | Tags: AMR, epitaxial, FMR, Magnetic force microscopy, Magnetism, nanomagnets, perovskite, scanning probe
@mastersthesis{Cunliffe2009,
title = {Magnetoelectric cobalt ferrite/bismuth ferrite hybrid nanostructures: Progress towards achieving electric field control of magnetization},
author = {Alexandra R. Cunliffe},
url = {http://www.nano.northwestern.edu/wp-content/uploads/2017/09/Senior_Thesis.pdf},
year = {2009},
date = {2009-05-01},
keywords = {AMR, epitaxial, FMR, Magnetic force microscopy, Magnetism, nanomagnets, perovskite, scanning probe},
pubstate = {published},
tppubtype = {mastersthesis}
}
Irma Kuljanishvili; Dmitriy A. Dikin; Sergey Rozhok; Scott Mayle; Venkat Chandrasekhar
Controllable Patterning and CVD Growth of Isolated Carbon Nanotubes with Direct Parallel Writing of Catalyst Using Dip-Pen Nanolithography Journal Article
In: Small, vol. 5, no. 22, pp. 2523–2527, 2009, ISSN: 16136810, 16136829.
Links | BibTeX | Tags: Nanotube, scanning probe
@article{kuljanishvili_controllable_2009,
title = {Controllable Patterning and CVD Growth of Isolated Carbon Nanotubes with Direct Parallel Writing of Catalyst Using Dip-Pen Nanolithography},
author = { Irma Kuljanishvili and Dmitriy A. Dikin and Sergey Rozhok and Scott Mayle and Venkat Chandrasekhar},
url = {http://doi.wiley.com/10.1002/smll.200900841},
doi = {10.1002/smll.200900841},
issn = {16136810, 16136829},
year = {2009},
date = {2009-01-01},
urldate = {2015-10-23},
journal = {Small},
volume = {5},
number = {22},
pages = {2523--2527},
keywords = {Nanotube, scanning probe},
pubstate = {published},
tppubtype = {article}
}
Udai Raj Singh; Anjan K. Gupta; Goutam Sheet; Venkat Chandrasekhar; H. W. Jang; C. B. Eom
Pseudogap formation in the metallic state of La0.7Sr0.3MnO3 thin films Journal Article
In: Applied Physics Letters, vol. 93, no. 21, pp. 212503, 2008, ISSN: 0003-6951, 1077-3118.
Links | BibTeX | Tags: Andreev reflection, point contact, scanning probe, Superconductivity
@article{singh_pseudogap_2008,
title = {Pseudogap formation in the metallic state of La0.7Sr0.3MnO3 thin films},
author = { Udai Raj Singh and Anjan K. Gupta and Goutam Sheet and Venkat Chandrasekhar and H. W. Jang and C. B. Eom},
url = {http://aip.scitation.org/doi/10.1063/1.3028072},
doi = {10.1063/1.3028072},
issn = {0003-6951, 1077-3118},
year = {2008},
date = {2008-11-01},
urldate = {2016-12-28},
journal = {Applied Physics Letters},
volume = {93},
number = {21},
pages = {212503},
keywords = {Andreev reflection, point contact, scanning probe, Superconductivity},
pubstate = {published},
tppubtype = {article}
}
Yongho Seo; Paul Cadden-Zimansky; Venkat Chandrasekhar
Low-temperature scanning force microscopy using a tuning fork transducer Journal Article
In: JOURNAL-KOREAN PHYSICAL SOCIETY, vol. 50, no. 2, pp. 378, 2007.
Links | BibTeX | Tags: scanning probe, Tuning fork
@article{seo_low-temperature_2007,
title = {Low-temperature scanning force microscopy using a tuning fork transducer},
author = { Yongho Seo and Paul Cadden-Zimansky and Venkat Chandrasekhar},
url = {https://www.researchgate.net/profile/Yongho_Seo/publication/1852213_Low-temperature_scanning_probe_microscopy_using_a_tuning_fork_transducer/links/02e7e528341b71ee62000000.pdf},
year = {2007},
date = {2007-01-01},
urldate = {2016-12-28},
journal = {JOURNAL-KOREAN PHYSICAL SOCIETY},
volume = {50},
number = {2},
pages = {378},
keywords = {scanning probe, Tuning fork},
pubstate = {published},
tppubtype = {article}
}
Kenneth Turner; Emma Tevaarwerk; Venkat Chandrasekhar; R. P. H. Chang
The scanning probe microscope and nanoscale measurement Journal Article
In: 2006.
Links | BibTeX | Tags: education, scanning probe
@article{turner_scanning_2006,
title = {The scanning probe microscope and nanoscale measurement},
author = { Kenneth Turner and Emma Tevaarwerk and Venkat Chandrasekhar and R. P. H. Chang},
url = {http://search.proquest.com/openview/d45377620a0bf37d9a6ccfb255aa727b/1.pdf?pq-origsite=gscholar&cbl=40590},
year = {2006},
date = {2006-01-01},
urldate = {2016-12-28},
keywords = {education, scanning probe},
pubstate = {published},
tppubtype = {article}
}
Yongho Seo; Paul Cadden-Zimansky; Venkat Chandrasekhar
Low-temperature high-resolution magnetic force microscopy using a quartz tuning fork Journal Article
In: Applied Physics Letters, vol. 87, no. 10, pp. 103103, 2005, ISSN: 00036951.
Links | BibTeX | Tags: Magnetic force microscopy, scanning probe, Tuning fork
@article{seo_low-temperature_2005,
title = {Low-temperature high-resolution magnetic force microscopy using a quartz tuning fork},
author = { Yongho Seo and Paul Cadden-Zimansky and Venkat Chandrasekhar},
url = {http://scitation.aip.org/content/aip/journal/apl/87/10/10.1063/1.2037852},
doi = {10.1063/1.2037852},
issn = {00036951},
year = {2005},
date = {2005-01-01},
urldate = {2015-10-23},
journal = {Applied Physics Letters},
volume = {87},
number = {10},
pages = {103103},
keywords = {Magnetic force microscopy, scanning probe, Tuning fork},
pubstate = {published},
tppubtype = {article}
}
Sung-Wook Chung; David S. Ginger; Mark W. Morales; Zhengfan Zhang; Venkat Chandrasekhar; Mark A. Ratner; Chad A. Mirkin
Top-Down Meets Bottom-Up: Dip-Pen Nanolithography and DNA-Directed Assembly of Nanoscale Electrical Circuits Journal Article
In: Small, vol. 1, no. 1, pp. 64–69, 2005, ISSN: 16136810.
Links | BibTeX | Tags: dip-pen nanolithography, molecular devices, scanning probe
@article{chung_top-down_2005,
title = {Top-Down Meets Bottom-Up: Dip-Pen Nanolithography and DNA-Directed Assembly of Nanoscale Electrical Circuits},
author = { Sung-Wook Chung and David S. Ginger and Mark W. Morales and Zhengfan Zhang and Venkat Chandrasekhar and Mark A. Ratner and Chad A. Mirkin},
url = {http://doi.wiley.com/10.1002/smll.200400005},
doi = {10.1002/smll.200400005},
issn = {16136810},
year = {2005},
date = {2005-01-01},
urldate = {2016-12-29},
journal = {Small},
volume = {1},
number = {1},
pages = {64--69},
keywords = {dip-pen nanolithography, molecular devices, scanning probe},
pubstate = {published},
tppubtype = {article}
}
S. Rozhok; S. Jung; V. Chandrasekhar; Xiwei Lin; Vinayak P. Dravid
Atomic force microscopy of nickel dot arrays with tuning fork and nanotube probe Journal Article
In: Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, vol. 21, no. 1, pp. 323, 2003, ISSN: 0734211X.
Links | BibTeX | Tags: nanomagnets, Nanotube, scanning probe, Tuning fork
@article{rozhok_atomic_2003,
title = {Atomic force microscopy of nickel dot arrays with tuning fork and nanotube probe},
author = { S. Rozhok and S. Jung and V. Chandrasekhar and Xiwei Lin and Vinayak P. Dravid},
url = {http://scitation.aip.org/content/avs/journal/jvstb/21/1/10.1116/1.1539066},
doi = {10.1116/1.1539066},
issn = {0734211X},
year = {2003},
date = {2003-01-01},
urldate = {2015-10-23},
journal = {Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures},
volume = {21},
number = {1},
pages = {323},
keywords = {nanomagnets, Nanotube, scanning probe, Tuning fork},
pubstate = {published},
tppubtype = {article}
}