There are three unique SPMs in my lab: a homemade Helium3-magnetic force microscope (He3-MFM), a variable temperature-MFM (VT-MFM), an ultrahigh vacuum-low temperature-scanning tunnel microscope (UHV-LT-STM).
Homemade He3-MFM with 14 T magnet
Our homemade He3-MFM is capable of high spatial resolution magnetic imaging with high sensitivity at ulra-low temperature (300 mK) with in situ high magnetic field (14 T), high voltage (1 kV), and transport measurements. The unique combination of in situ capabilities of our MFM allows us to explore novel magnetic and electric properties of almost any new materials at quantum limit.
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Base T: ~253 mK
Sample T: 350 mK-RT He-3 Holding Time 4K mode: ~88 h 1K mode: >150 h 14 T (Out-of-plane) High sensitivity in-situ transport in-situ high voltage |
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Homemade VT-MFM with in situ high magnetic/electric
fields
Our homemade VT-MFM is the only machine in the world that is capable of high spatial resolution magnetic imaging with high sensitivity in a wide temperature range (2-300 K) with in situ high magnetic field (8 T) and high voltage (1 kV). The unique combination of in situ capabilities of our MFM allows us to explore novel magnetic and electric properties of almost any new materials at extreme conditions. Examples include correlated net moments at multiferroic domain walls, magnetic inhomogeneity in ultra-thin magnetic films and unconventional pancake-like domains in multiferroics. In addition, we have developed unprecedented Magnetoelectric Force Microscopy (MeFM) for visualizing magnetoelectric domains with submicron resolution.
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Key features Variable T (2 - 300 K) & high H (8 T) High vacuum (<10-6 mbar) High resolution (50 - 100 nm) High sensitivity (~  )Mmin ~  Antiferromagnetic domain walls in-situ high voltage (1 kV) 10 MV/m for thickness ~ 0.1 mm MeFM in-situ transport AHE, THE, etc. |
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MFM inside
8 T magnet
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MFM head
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- UHV-LT-STM
An ultra-high-vacuum low temperature scanning tunnerling microscope (UHV-LT-STM) from Omicron Nanotechnology has been installed in our SPM lab. The system consists of a LT-STM analysis chamber, and dedicate preparation chamber and a load-lock (FEL). The base pressure of the STM chamber is below 1e-11 mbar. The base temperature is 4.5 K. The dedicate preparation chamber for in situ tip and surface preparation is installed. In collaboration with Prof. M. Bode at the Universitate Wuerzburg, we are developing a novel spin polarized-STM (SP-STM) technique to visualize atomic scale magnetic structure in novel magnetic materials.
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Key features
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UHV-LT-STM |
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Room temperature AFM
A multi-mode atomic force microscope (MM-AFM, Bruker) with an extender that is capable of all AFM modes (contact, tapping, PFM, MFM/EFM, SSPM, cAFM, etc.) at ambient condition. The commercial unit is connected with dedicate electric cables for high sensitivity background-free piezoresponse force microscopy (PFM) measurements (~0.1 pm/V with 5 V modulation) using a dedicate lock-in amplifier (SR 830).
Other SPM facilities
Besides developing experimental tools and techniques in-house, we are also collaborating with facility scientists in the Center for Nanoscale Materials (CNM) at Argonne National Laboratory (ANL) to expand our SPM capabilities by utilizing their advanced SPM instruments. At the same time, we are implementing various advanced SPM techniques at CNM so that other facility users from the research community can benefit from our SPM expertise.