Suppression of low-temperature magnetic states in Mn3O4 nanoparticles

Sonochemical synthesis and chracterization of Mn3O4 nanoparticles

“…A typical TEM micrograph and size distribution histogram of particle size in the range of 15-25 nm can be found in [28]. The opposite signs of first derivatives of magnetization with respect to T confirms that the magnetic phase transition is at about 42 K. Additionally, the first derivative characteristics are similar to those found in Winkler's [29] study.…”

“…The saturation magnetization (M s ) was not reached, showing a maximum magnetization (M max ) at about 34.81 emu g -1 at 10 K, which is smaller than the saturation magnetization of bulk Mn 3 O 4 [32,33]. The smaller Ms values in nanoparticles are generally attributed to the core-shell structure with aligned 19 nm is 42 K. Both Winkler et al [29] and Regmi et al [28] reported T c to be 42 K for Mn 3 O 4 with average size of 15 nm in diffrent studies, which is in consistency with our observations. A detailed explanation about the nonvarying magnetic transition temperature for Mn 3 O 4 with …”

Polyol synthesis of (polyvinylpyrrolidone) PVP–Mn3O4 nanocomposite

“…A detailed study on magnetic transition temperatures for 15-25 nm Mn 3 O 4 nanoparticles can be found in Refs. [24,25]. The opposite sign of first derivatives of magnetization with respect to elevated temperatures verifies the magnetic phase transition at about 42 K. This first derivative characteristics are similar to that reported by Winkler et al [24].…”

A Green Chemical Synthesis and Characterization of Mn3O4 nanoparticles

“…Figure 5 shows a room temperature magnetization curve of the sample that exhibits linear behavior with the field and has negligible coercivity and saturation up to 15 kOe. These observations can be attributed to the superparamagnetic feature of the particles with grain sizes smaller than 20 nm [37]. The hysteresis in the single-domain ferrimagnetic particles disappears when the particle size becomes so small that the maximum anisotropy energy becomes close to the thermal energy.…”