Using multi-step high performance liquid chromatography (HPLC) it was possible to prepare a chromatographically pure sample of N@C₆₀. Invoking EPR spectroscopy of solid samples prepared after each HPLC step, the increase of relative N@C₆₀ concentration could unambiguously be determined. The UV/Vis spectrum of N@C₆₀ is indistinguishable within experimental error from that of C₆₀, confirming negligible coupling between nitrogen in its atomic ground state and C₆₀ cage molecular wave functions. The observed large dipolar width of the EPR spectrum of the pure paramagnetic compound indicates weak spin exchange between neighboring paramagnetic centers which is further proof for a very small spin transfer from the encapsulated atom to the fullerene cage.

InAs nanowires are grown epitaxially by catalyst-free metal organic vapor phase epitaxy and are subsequently positioned with a lateral accuracy of less than 1 μm using simple adhesion forces between the nanowires and an indium tip. The technique, requiring only an optical microscope, is used to place individual nanowires onto the corner of a cleaved-edge wafer as well as across predefined holes in Si3N4 membranes. The precision of the method is limited by the stability of the micromanipulators and the precision of the optical microscope.