Size Dependence of Structures and Properties of Magnetic Materials

Abstract

Due to the involvement of high portion of atomic coordination imperfection in surfaces and interfaces, the properties of magnetic nanocrystals dramatically differ from that of the corresponding bulk counterparts, which have led to a surge in both experimental and theoretical investigations in the past decades. This review summarizes the studies for these size-dependent magnetic properties, and additional thermal or phase stabilities, and mechanical properties. To interpret the above phenomena, a thermodynamic model for the size dependence and interface dependences of these properties is described, which is based on Lindemann s criterion for melting, Mott s expression for the vibrational melting entropy, and Shi s model for the size-dependent melting temperature. The model without any adjustable parameter is confirmed by a large number of experimental results, and helps us to understand the structures and properties of the magnetic nanocrystals. Moreover, other theoretical works on the above properties are also mentioned and commented.

Synthesis, Characterization and Imaging of Fluorescine Isothiocyanate Conjugated Magnetite Nanoparticles in MCF 7 Breast Cancer Cell Lines

“…In the case of Fe 3 O 4 conjugated FITC, fi gure 3F the Ms value decreased to about 40 emug -1 indicating that FITC coating can lead to the formation of a nonmagnetic layer on top of the magnetic core which can consequently decrease the magnetization of the nanoparticles [19]. It is reported in the literature that Ms of iron-oxide nanoparticles increases with increase in particle size [5,7,32]. In addition, it may also be due to different chemical inactive layer with the magnetic fi eld.…”

“…It is well known that biomarkers ( wide research attention [5][6][7]. These unique materials have been utilized successfully for number of applications including contrast-enhanced imaging [8,9] and drug delivery due to their magnetic nature which can be manipulated by an external magnetic fi eld [10,11].…”

Multifunctional Nanoplatform for Targeted Laser-induced Hyperthermia and Microscopy of Breast Cancer Cells using SPION-based Gold and Folic Acid Conjugated Nanodendrimers: An in vitro Assay

“…Small magnetite nanoparticles (<15 nm) is called superparamagnetic iron oxide nanoparticle (SPION), which lacks a hysteresis loop and possess high field irreversibility, high saturation field and extra anisotropy contributions [5,6]. Over the past decades SPIONs with size and morphology dependent physical and chemical properties including biocompatibility, chemical composition, magnetic behavior, surface structure, adsorption properties, solubility, low toxicity, good magnetic response have attracted world-wide research attention [7,8]. These unique materials have been utilized successfully for number of applications including contrast-enhanced imaging [9] and drug delivery [10].…”

Effect of Laser Wavelengths on Drug Release with and without Gold Nanoshells and Magnetic Guidance on Uptake by Cancer Cells

“…In a research, liposomes contrast agent has been utilized for drug release and photoacoustic imaging applications, which showed these can have better contrast at a depth of about 2-cm [9]. Superparamagnetic iron oxide nanoparticle (SPION) with their significant physicochemical properties such as absence of hysteresis loop, high field irreversibility, high saturation field, extra anisotropy contributions, chemical composition, granulometric uniformity, crystal structure, surface structure, adsorption properties, solubility and low toxicity and, particles size with overall narrow uniform size distribution have made them a serious and reliable candidate for in various fields, such as biomedical applications [10][11][12]. In magnetically responsive nanoparticles (MNPs), NPs are encapsulated or embedded in a larger colloidal structure that carries a drug.…”