title: Superparamagnetic Properties of Hemozoin.
abstract: We report that hemozoin nanocrystals demonstrate superparamagnetic properties, with direct measurements of the synthetic hemozoin magnetization. The results show that the magnetic permeability constant varies from μ = 4585 (at -20 °C) to 3843 (+20 °C), with the values corresponding to a superparamagnetic system. Similar results were obtained from the analysis of the diffusion separation of natural hemozoin nanocrystals in the magnetic field gradient, with μ = 6783 exceeding the value obtained in direct measurements by the factor of 1.8. This difference is interpreted in terms of structural differences between the synthetic and natural hemozoin. The ab initio analysis of the hemozoin elementary cell showed that the Fe(3+) ion is in the high-spin state (S = 5/2), while the exchange interaction between Fe(3+) electron-spin states was much stronger than kBT at room temperature. Thus, the spin dynamics of the neighboring Fe(3+) ions are strongly correlated, lending support to the superparamagnetism.
authors.affiliation: Universidad Central del Caribe, Bayamón, PR 00960-6032, USA.
authors.forename: M
authors.initials: M
authors.lastname: Inyushin
authors.affiliation: Universidad Central del Caribe, Bayamón, PR 00960-6032, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kucheryavih
authors.affiliation: Universidad Central del Caribe, Bayamón, PR 00960-6032, USA.
authors.forename: L
authors.initials: L
authors.lastname: Kucheryavih
authors.affiliation: Universidad Central del Caribe, Bayamón, PR 00960-6032, USA.
authors.forename: L
authors.initials: L
authors.lastname: Rojas
authors.affiliation: University of the Algarve, FCT, DQB and CIQA, 8005-139, Faro, Portugal.
authors.forename: I
authors.initials: I
authors.lastname: Khmelinskii
authors.affiliation: University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA.
authors.forename: V
authors.initials: V
authors.lastname: Makarov
mesh_terms: D055598:Chemical Phenomena; D006420:Hemeproteins / Q000737:chemistry*; D008280:Magnetics; D013696:Temperature
chemical_list: D006420:Hemeproteins; C020753:hemozoin