Low Temperature Scanning Probe Microscope(LT-SPM) operating in a Cryogen-Free Cryostat, 1.5-300K

We present the design of a Low Temperature Scanning Probe Microscope(LT-SFM) operating in a vibration-free cryogen-free cryostat. A 0.5W ultra now noise Pulse Tube cryocooler is integrated into the cryostat with a 9T magnet. Stick slip coarse approach mechanism is used to bring the sample in to close proximity of the sample. The sample can be moved in XY directions within 3 mm range, while the position is measured with capacitive encoder with 3$\mu $m accuracy. An improved fiber interferometer with $\sim $12fm/$\surd $Hz noise level is used to detect cantilever deflection. The resonance of the cantilever controlled by a digital Phase Locked Loop (PLL) integrated in our Control Electronics with 5mHz frequency resolution. We can achieve $\sim $1nm resolution in AFM mode {\&} $<$10nm resolution in MFM mode. Results from different imaging modes; non-contact AFM, MFM, Piezoresponse, Conductive AFM etc. will be presented.