  We introduce a scattering-type scanning near-field infrared microscope
(s-SNIM) for the local scale near- field sample analysis and spectroscopy from
room (RT) down to liquid helium (LHe) temperatures. The extension of s-SNIM
down to T = 5K is in particular crucial for low-temperature phase transitions,
e.g. for the examination of superconductors, as well as low energy excitations.
The LT s-SNIM performance is tested with CO2-IR excitation at T = 7K using a
bare Au reference and a structured Si/SiO$_2$-sample. Furthermore, we quantify
the impact of local laser heating under the s-SNIM tip apex by monitoring the
light-induced ferroelectric-to-paraelectric phase transition of the
skyrmion-hosting multiferroic material GaV4S8 at T$_c$ = 42K. We apply LT
s-SNIM to study the spectral response of GaV$_4$S$_8$ and its lateral domain
structure in the ferroelectric phase by the mid-IR to THz free-electron
laser-light source FELBE at the Helmholtz-Zentrum Dresden-Rossendorf, Germany.
Notably, our s-SNIM is based on a non-contact atomic force microscope(AFM), and
thus can be complemented in-situ by various other AFM techniques, such as
topography profiling, piezo-response force microscopy (PFM) and/or Kelvin-probe
force microscopy (KPFM). The combination of these methods support the
comprehensive study of the mutual interplay in the topographic, electronic and
optical properties of surfaces from room temperature down to 5K.

Instrumentation and Detectors;Applied Physics;Optics