電磁熱療系統是治療惡性腫瘤方法中的一項新技術，係藉由磁生熱效應誘發熱療針體燒灼腫瘤，達到破壞的目的。軟磁性鐵基非晶質合金具有高飽和磁化強度、低矯頑磁力以及顯著的異常渦電流損耗，指出鐵基非晶質合金具有成為熱療針材料的潛力。本實驗選用Fe-B-Y-Nb四元合金系統，探討B與Nb含量對玻璃形成能力、磁特性與升溫能力的影響。
Fe-B-Y-Nb金屬玻璃經由真空電弧爐融煉製得，以調整B含量Fe64.5+XB27-XY4.5Nb4 (X=0, 1, 2, 3, 4)、Nb含量Fe66.5+YB25Y4.5Nb4-Y (Y=0, 0.5, 1, 1.5)兩個系列合金。進行X光繞射分析、EBSD析出相鑑定、SEM-BE影像攝影、DSC吸放熱圖譜以及VSM磁滯曲線測量。在B系列合金中，Fe66.5B25Y4.5Nb4存在最少的NbBFe析出物，析出物佔總面積的0.70%。其過冷液相區∆Tx為95，是B系列合金裡玻璃形成能力較好的成分。同時，Fe66.5B25Y4.5Nb4也具有好的軟磁性，飽和磁化強度90.7 emu/g，矯頑磁力5.4 A/m。將Fe66.5B25Y4.5Nb4置於變動磁場下5公分進行升溫，最高溫度可達117 oC。Nb系列合金中，Fe67B25Y4.5Nb3.5進一步的提升玻璃形成能力，析出物佔總面積的0.08%，過冷液相區∆Tx為97。其飽和磁化強度增強至96.3 emu/g，矯頑磁力稍增為10.7 A/m。將Fe67B25Y4.5Nb3.5置於變動磁場下5公分進行升溫，最高溫度攀升到132oC。
B系列合金中，較少的NbBFe析出相促成飽和磁化強度高且矯頑磁力小的磁性質，使得Fe66.5B25Y4.5Nb4擁有突出的升溫能力。Nb系列合金裡，Nb含量的減少抑制了NbBFe相析出，飽和磁化強度隨之增強；同時也助長Y2O3相的成長，擴大了合金的矯頑磁力。在磁特性與析出物相互消長的的情況下，Fe67B25Y4.5Nb3.5成為本實驗中升溫能力最佳的合金。

Electromagnetic thermoablation is a new kind therapy for tumor. Soft magnetic bulk metallic glass is considered as a potential material for thermotherapy needle in electromagnetic thermoablation due to its high saturation magnetization (Ms), low coercivity (Hc) and high unusual eddy current loss. In this study Fe-B-Y-Nb alloys are selected as experimental materials of soft magnetic bulk metallic glass. The effect of Boron and Niobium content is investigated on the glass forming ability (GFA), magnetic property and heating ability in quaternary Fe-B-Y-Nb system.
Fe-B-Y-Nb metallic glass was formed by Arc Melting. It was a function of B content in Fe68.4B28-XY4.6Nb4 (X=0, 1, 2, 3, 4) and Nb content in Fe66.5+YB25Y4.5Nb4-Y (Y=0, 0.5, 1, 1.5) alloys. The glass forming ability and thermal property were studied by differential scanning calorimetry (DSC). The phase and microstructure were characterized by X-ray diffractometer (XRD) ,SEM-BE imgage and electron backscatter diffraction (EBSD), respectively. In addition, the magnetic property were measured by Vibrating Sample Magnetometer (VSM). The experiment for heating ability was all under the condition with 5cm distance away from coil which applied alterative magnetic field.
It is observed that Fe66.5B25Y4.5Nb4 alloy exhibits better GFA than other B content alloys with supercooled liquid region (Tx) 95. In Nb series alloys, Fe67B25Y4.5Nb3.5 alloy shows the best GFA in the study with Tx 97. According to hysteresis loop, Ms and Hc is 90.7 emu/g, 5.4 A/m for Fe66.5B25Y4.5Nb4 alloy, and 96.3 emu/g ,10.7 A/m for Fe67B25Y4.5Nb3.5 alloy. Owing to high Ms and low Hc, the heating ability can reach high temperature as Fe66.5B25Y4.5Nb4 alloy can reach 117oC and Fe67B25Y4.5Nb3.5 alloy can reach 132 oC.
In the B series alloys, less NbBFe causes high Ms and narrow Hc. Therefore, B25 alloy exhibites better heating ability. In the Nb series alloys, NbBFe is suppressed to enhance Ms, but Y2O3 grew to broaden Hc by reducing Nb content. Due to ebb and rise of soft magnetic property with precipitation, Fe67B25Y4.5Nb3.5 exhibited the greatest heating ability in the study.

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