Final Report Summary - BMR (Ballistic magnetoresistance in thin film nanocontacts)
Leading-edge nanofabrication techniques such as optical, electron beam, nanoimprinting as well as Focused ion beam (FIB) lithography along with state-of-the-art thin film deposition could be deployed for the fabrication of thin film nanoconstrictions. The Ballistic magnetoresistance in thin film nanocontacts (BMR) project's aim was twofold, namely the fabrication of thin film nanoconstrictions by developing and implementing the above-mentioned techniques as well as the research into the ballistic magnetoresistive and spin-transport properties in thin film nanocontacts.
The project idea stemmed from formerly prominent publications with regard to BMR properties in nanowire contacts. The BMR consortium comprises European leading experimentalists from the Superior Council for Scientific Research (CSIC) who engage in the portfolio of BMR in wire nanocontacts, eminent BMR theoretical physicists from Kazan State University (KSU), the Council for the Central Laboratory of the Research Councils (CCLRC) which provided its laboratories in which state-of-the-art nanofabrication techniques are deployed. Furthermore, the consortium consists of scientists from the University of Plymouth who engage in the study of the magneto-transport properties of thin films and devices as well as distinguished researchers from the Institute of Applied Physics (IAP) of the University of Hamburg who devoted in the study of spin-injection and spin-transport properties.
The major achievements of the project are outlined below:
- Fabrication of CIP and CPP nanoconstrictions by dint of the deployment of electron beam nanofabrication and nanoimprinting techniques;
- Magneto-transport and nanoscale characterisation of constriction devices;
- FIB nanofabrication and in-situ magneto-transport measurement in thin film nanoconstrictions;
- Study of BMR behaviour in various nanocontacts.
Notwithstanding the experimental data which stemmed from the laboratories, there has not been any incontrovertible experimental evidence of the existence of BMR. The results indicate that magnetoresistance reaches a peak at constriction sizes of 20 nm while it starts to decrease as the constriction size obtains smaller values. The latter result, if juxtaposed with the BMR theory, leads to a contradiction since BMR theory predicts that the ballistic magnetoresistance may be obtained in the ballistic transport regime where the constriction size is smaller than the mean-free path of the conduction electrons.
The project idea stemmed from formerly prominent publications with regard to BMR properties in nanowire contacts. The BMR consortium comprises European leading experimentalists from the Superior Council for Scientific Research (CSIC) who engage in the portfolio of BMR in wire nanocontacts, eminent BMR theoretical physicists from Kazan State University (KSU), the Council for the Central Laboratory of the Research Councils (CCLRC) which provided its laboratories in which state-of-the-art nanofabrication techniques are deployed. Furthermore, the consortium consists of scientists from the University of Plymouth who engage in the study of the magneto-transport properties of thin films and devices as well as distinguished researchers from the Institute of Applied Physics (IAP) of the University of Hamburg who devoted in the study of spin-injection and spin-transport properties.
The major achievements of the project are outlined below:
- Fabrication of CIP and CPP nanoconstrictions by dint of the deployment of electron beam nanofabrication and nanoimprinting techniques;
- Magneto-transport and nanoscale characterisation of constriction devices;
- FIB nanofabrication and in-situ magneto-transport measurement in thin film nanoconstrictions;
- Study of BMR behaviour in various nanocontacts.
Notwithstanding the experimental data which stemmed from the laboratories, there has not been any incontrovertible experimental evidence of the existence of BMR. The results indicate that magnetoresistance reaches a peak at constriction sizes of 20 nm while it starts to decrease as the constriction size obtains smaller values. The latter result, if juxtaposed with the BMR theory, leads to a contradiction since BMR theory predicts that the ballistic magnetoresistance may be obtained in the ballistic transport regime where the constriction size is smaller than the mean-free path of the conduction electrons.
