Synthesis, Magnetic Properties, and Relaxivity of CoFe@C and NiFe@C Nanocomposites
Abstract
Core–shell CoFe@C and NiFe@C nanocomposites were prepared by gas-condensation synthesis. CoFe@C and NiFe@C particles had bcc and fcc cores, respectively. The treatment of these nanocomposites with hydrochloric acid revealed that they are more chemically stable than Fe@C composites. The maximum specific magnetization of CoFe@C and NiFe@C nanocomposites at room temperature in the field with a strength of 27 kOe was 125 and 58 G cm3/g, respectively. The processes of longitudinal and transverse relaxation of nuclear proton spins of aqueous suspensions of nanocomposites in various magnetic fields (0.5, 1, and 2 kOe) were studied. NiFe@C and CoFe@C nanocomposites have high transverse relaxivity values and can be used as magnetic markers for detection of low concentrations of bioobjects by NMR relaxometry.
- Publication:
-
Physics of Metals and Metallography
- Pub Date:
- March 2019
- DOI:
- 10.1134/S0031918X19030037
- Bibcode:
- 2019PMM...120..254B
- Keywords:
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- nanocomposite;
- magnetic properties;
- relaxivity