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PhD házivédésDatz DánielMTA Wigner FK SZFIExperimental and numerical 
investigations of the near-field scattering of boron nitride based 
nanomaterials2023. július 18. kedd, 10.00, KFKI Telephely, I. épület 1. 
emeleti TanácsteremBoron nitride nanomaterials exhibit interesting optical 
properties in the mid-infrared region. Near-field infrared spectroscopy opens 
the way of probing these properties with 10-20 nm spatial resolution. This 
method is especially suitable for the investigation of small molecules 
encapsulated in boron nitride nanotubes. In this presentation, I show my 
results on near-field probing of boron nitride nanotubes in different stages 
of their filling process. First, the nanotubes have to be cleaned and their 
caps opened. This process introduces various defects to the nanotube. I show 
the defect structure of an isolated, multi-walled boron nitride nanotube, 
demonstrating the nanoscale resolution on truly nano-sized scatterers. Then, 
I demonstrate the possibility to investigate the products of chemical 
reactions between encapsulated molecules in nano-sized cavities in boron 
nitride nanotubes in-situ with 20 nm spatial resolution. The unique 
dielectric properties of BNNT resonantly enhances the near field signal 
allowing the detection of the signal of a small number of molecules.Lastly, I 
present a theoretical description of the scattering process based on the 
extension of the classical Mie theory. In this formalism, the electric field 
is expanded as the linear combination of spherical harmonics centered around 
the scattering particles. This so-called multipole reflection theory (MRT) is 
able to describe the scattering properties of multiple particles in the 
vicinity of an interface. I show the applicability of the multipole 
reflection model for near-field calculations by applying it to measurements 
of boron nitride materials.Join Zoom 
Meetinghttps://wigner-hu.zoom.us/j/81058498589?pwd=QkdRL0ZHN2ZxaGJTczNqRWYrSGJ5Zz09Meeting
 ID: 810 5849 8589Passcode: 455606 Minden érdeklődőt szívesen látunk! - 
Everyone is welcome to attend.Nagy Attilasem-admin AT szfki.hu