Synthesis and characterization of coprecipitation-derived ferrimagnetic glass-ceramic
Synthesis and characterization of coprecipitation-derived ferrimagnetic glass-ceramic
复制标题
共沉淀亚铁磁玻璃陶瓷的合成与表征
DOI：
10.1007/s10853-005-2636-x
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
E. Verné
中科院分区：
文献类型：
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作者：
O. Bretcanu;S. Spriano;C. Vitale;E. Verné
亚铁磁微晶玻璃可用于磁感应热疗。该技术用于通过应用交变磁场来破坏实体肿瘤疾病。生物相容性亚铁磁材料可以很容易地融入肿瘤，并且主要通过磁滞损耗产生热量。通过熔化共沉淀原料，制备了SiO2-Na2O-CaO-P2O5-FeO-Fe2O3体系中的亚铁磁玻璃陶瓷。这种玻璃陶瓷含有独特的结晶相磁铁矿，嵌入非晶态基质中。从熔化温度冷却期间，磁铁矿晶体沉淀。这种玻璃陶瓷不再需要任何成核和生长热处理，因为在冷却过程中产生了最大数量的磁铁矿晶体。使用两种不同的方法评估玻璃陶瓷样品中的平均晶胞参数、磁铁矿微晶尺寸和晶相的数量比。两种方法都获得了类似的结果。磁铁矿晶体的尺寸约为 50 纳米。样品中含有 45 wt% 的磁铁矿，均匀分布在非晶残余基体中。所制备的微晶玻璃的饱和磁化强度为 34 A·m2/kg，矫顽力为 6.7 kA/m。在高达 796 kA/m 的磁场下，估计磁损耗/周期约为 1.45 mJ/g。该玻璃陶瓷在 40 kA/m 磁场和 440 kHz 频率下的比功率损耗为 25 W/g。该材料表现出生物活性行为，在模拟体液中浸泡 2 周后，观察到其表面形成羟基磷灰石层。这一特性使其也适用于骨癌。
Ferrimagnetic glass-ceramics could be used for magnetic induction hyperthermia. This technique is utilised for the destruction of solid neoplastic diseases by application of an alternating magnetic field. Biocompatible ferrimagnetic materials could be easily incorporated into a tumour and could generate heat mainly by hysteresis loss.A ferrimagnetic glass-ceramic in the system SiO2–Na2O–CaO–P2O5–FeO–Fe2O3has been prepared by melting of the coprecipitation-derived raw materials. This glass-ceramic contains a unique crystalline phase, magnetite, embedded in an amorphous matrix. Magnetite crystals precipitate during cooling from melting temperature. This glass-ceramic would no longer require any nucleation and growth thermal treatment, since the maximal quantity of magnetite crystals was produced during cooling. The average unit-cell parameter, crystallite size of magnetite, and the quantitative ratio of the crystallographic phases in the glass-ceramic samples were evaluated using two different methods. Similar results were obtained with both methods. The magnetite crystals are about 50 nm in dimensions. The samples contain 45 wt% of magnetite, homogeneously distributed in the amorphous residual matrix.The as prepared glass-ceramic has a saturation magnetisation of 34 A·m2/kg and a coercive force of 6.7 kA/m. The estimated magnetic loss/cycle under the magnetic field up to 796 kA/m is around 1.45 mJ/g. The specific power loss of this glass-ceramic under a magnetic field of 40 kA/m and a frequency of 440 kHz is 25 W/g.This material showed a bioactive behaviour, as after 2 weeks of soaking in a simulated body fluid the formation of a hydroxylapatite layer on their surface was observed. This feature makes it also suitable for bone cancer.