Prodotti della ricerca

 
Titolo: Hysteretic NanoSQUID Sensors for Investigation of Iron Oxide Nanoparticles
Autori: 
Data di pubblicazione: 2013
Rivista: 
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY  
Abstract: Magnetic nanosensors based on niobium nano superconducting quantum interference device (nanoSQUID) have been fabricated and employed to investigate the magnetic properties of iron oxide nanoparticles. The nanoSQUIDs, fabricated by electron beam lithography, consist in a square loop interrupted by two nanometric constrictions (Dayem bridges). The flux capture area is 0.5 mu m(2) while the Dayem nanobridges have a width and a length ranging from 50 to 90 nm and 70 to 80 nm, respectively. Measurements of current to voltage (I-V) and critical current to magnetic flux (I-C-Phi) characteristics have been reported for different nanobridge dimensions. At T = 4.2 K the nanosensors have shown a hysteretic I-V characteristic and a triangular shaped I-Phi pattern suggesting a strong deviation from sinusoidal current-phase relationship. Due to the hysteretic behavior, the devices have been employed as a magnetic flux to current transducer. In such a configuration an overall magnetic flux resolution of about 0.3 m Phi(0) has been estimated. These nanosensors have been successfully employed to measure the field dependence and the time relaxation of the magnetization of iron oxide nanoparticles having a mean diameter of 4.2 nm. The experimental curves undoubtedly prove that the nanoSQUIDs reported here can be successfully employed to investigate the magnetic properties of very small nanoparticles. RI Peddis, Davide/J-8556-2013; Russo, Roberto/A-8576-2010 OI Russo, Roberto/0000-0001-9431-6265
Handle: http://hdl.handle.net/11584/103823
Tipologia:1.1 Articolo in rivista

File in questo prodotto:
Non ci sono file associati a questo prodotto.
credits unica.it | accessibilità Università degli Studi di Cagliari
C.F.: 80019600925 - P.I.: 00443370929
note legali | privacy

Nascondi la toolbar