English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We demonstrate the operation of low-noise nano superconducting quantuminterference devices (SQUIDs) based on the high critical field and highcritical temperature superconductor YBa$_2$Cu$_3$O$_7$ (YBCO) asultra-sensitive magnetometers for single magnetic nanoparticles (MNPs). ThenanoSQUIDs exploit the Josephson behavior of YBCO grain boundaries and havebeen patterned by focused ion beam milling. This allows to precisely define thelateral dimensions of the SQUIDs so as to achieve large magnetic couplingbetween the nanoloop and individual MNPs. By means of focused electron beaminduced deposition, cobalt MNPs with typical size of several tens of nm havebeen grown directly on the surface of the sensors with nanometric spatialresolution. Remarkably, the nanoSQUIDs are operative over extremely broadranges of applied magnetic field (-1 T $< \mu_0 H <$ 1 T) and temperature (0.3K $< T<$ 80 K). All these features together have allowed us to performmagnetization measurements under different ambient conditions and to detect themagnetization reversal of individual Co MNPs with magnetic moments (1 - 30)$\times 10^6\,\mu_{\rm B}$. Depending on the dimensions and shape of theparticles we have distinguished between two different magnetic states yieldingdifferent reversal mechanisms. The magnetization reversal is thermallyactivated over an energy barrier, which has been quantified for the (quasi)single-domain particles. Our measurements serve to show not only the highsensitivity achievable with YBCO nanoSQUIDs, but also demonstrate that thesesensors are exceptional magnetometers for the investigation of the propertiesof individual nanomagnets.

NanoSQUID magnetometry of individual cobalt nanoparticles grown by focused electron beam induced deposition