Apparent magnetic energy-barrier distribution in horse-spleen ferritin: Evidence for multiple interacting magnetic entities per ferrihydrite nanoparticle
2002 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 65, no 2Article in journal (Refereed) Published
Magnetic viscosity measurements were made on native horse-spleen ferritin in zero applied magnetic field at temperatures between 21 and 21 K. The data have been used to calculate the apparent magnetic-moment-weighted energy barrier distribution for the sample of ferritin. The distribution is composed of a log-normal distribution plus a second distribution that is well described by an exponential decay of barrier frequency with increasing barrier height. The two distributions contribute approximately equally to the overall distribution. The log-normal distribution has its peak at an energy barrier of approximately 3 x 10(-21) J, while the decay constant for the second distribution has a value of approximately 2 x 10(-21) J. The existence of the low-energy barrier distribution with exponentially decaying shape in conjunction with the observation of shifted field-cooled magnetic hysteresis loops is interpreted as strong evidence for the existence of multiple interacting magnetic entities within each ferritin particle.
Place, publisher, year, edition, pages
2002. Vol. 65, no 2
macroscopic quantum coherence, antiferromagnetic ferritin, particles, proteins, spin, relaxation, cores
IdentifiersURN: urn:nbn:se:kth:diva-21254DOI: 10.1103/PhysRevB.65.024436ISI: 000173213100081OAI: oai:DiVA.org:kth-21254DiVA: diva2:339952
QC 201005252010-08-102010-08-10Bibliographically approved