On-chip Electron Spin Resonance (ESR) of magnetic molecules requires the ability to precisely position nanosized samples in antinodes of the electro-magnetic field for maximal magnetic interaction. A method is developed to entrap micro-crystals containing spins in a well defined location on a substrate's surface. Traditional cavity ESR measurements are then performed on a mesoscopic crystal at 34 GHz. Polycrystalline diluted Cr5+ spins were entrapped as well and measured while approaching the lower limit of the ESR sensitivity. This method suggests the feasibility of on-chip ESR measurements at dilution refrigerator temperatures by enabling the positioning of samples atop an on-chip superconducting cavity.
@article{arxiv.0908.3038,
title = {Entrapment of magnetic micro-crystals for on-chip electron spin resonance studies},
author = {N. Groll and S. Bertaina and M. Pati and N. S. Dalal and I. Chiorescu},
journal= {arXiv preprint arXiv:0908.3038},
year = {2009}
}