Nano-sized hematite (α-Fe2O3) is not well suited for magnetic heating via an alternating magnetic field (AMF) because it is not superparamagnetic—at its best, it is weakly ferromagnetic. However, manipulating the magnetic properties of nano-sized hematite (i.e., magnetic saturation (Ms), magnetic remanence (Mr), and coercivity (Hc)) can make them useful for nanomedicine (i.e., magnetic hyperthermia) and nanoelectronics (i.e., data storage). Herein we study the effects of size, shape, and crystallinity on hematite nanoparticles to experimentally determine the most crucial variable leading to enhancing the radio frequency (RF) heating properties. We present the synthesis, characterization, and magnetic behavior to determine the structure–property relationship between hematite nano-magnetism and RF heating. Increasing particle shape anisotropy had the largest effect on the specific adsorption rate (SAR) producing SAR values more than 6 × greater than the nanospheres (i.e., 45.6 ± 3 W/g of α-Fe2O3 nanorods vs. 6.89 W/g of α-Fe2O3 nanospheres), indicating α-Fe2O3 nanorods can be useful for magnetic hyperthermia.

中文翻译：

---

上赤铁矿（α-铁纳米结构效应₂ ö ₃）纳米颗粒射频加热

纳米赤铁矿（α-Fe2O3）不太适合通过交变磁场（AMF）进行磁性加热，因为它不是超顺磁性的，最好的情况下，它是弱铁磁性的。但是，操纵纳米尺寸赤铁矿的磁性（即磁饱和度（Ms），剩磁（Mr）和矫顽力（Hc））可以使它们用于纳米医学（即磁热疗）和纳米电子学（即数据）。贮存）。本文中，我们研究了尺寸，形状和结晶度对赤铁矿纳米颗粒的影响，以实验确定最关键的变量，从而提高了射频（RF）加热性能。我们介绍了合成，表征和磁行为，以确定赤铁矿纳米磁性和RF加热之间的结构-性质关系。