EPR/FMR, FTIR, X-Ray and Raman Investigations of Fe-Doped SiCN Ceramics
EPR/FMR, FTIR, X-Ray and Raman Investigations of Fe-Doped SiCN Ceramics
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DOI：
10.1007/s00723-010-0120-5
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发表时间：
2010-08-01
影响因子：
1
通讯作者：
Misra, Sushil K.
中科院分区：
文献类型：
--
作者：
Andronenko, S. I.;Stiharu, I.;Misra, Sushil K.
在600 ~ 1600 A ℃范围内，采用不同热解温度合成了Fe离子掺杂的SiCN磁性陶瓷。用电子顺磁共振/铁磁共振、拉曼、傅立叶变换红外和X射线衍射等技术检测了陶瓷的几个相：（a）随着温度从600 ℃升高到800 ℃，从聚合物态（Fe离子处于顺磁态）向陶瓷态转变;（B）在950- 1150 ℃范围内形成两种不同的Fe物质：铁磁状态的纳米晶体颗粒和超顺磁状态下结合到自由碳状态中的Fe离子;（c）在1150 ℃以上，游离碳含量减少，因此，与该相有关的宽Fe信号强度减少;（d）在约1200 ℃出现新的Fe相;（e）在约1400摄氏度时铁磁相消失;（f）在1530摄氏度以上时所有Fe离子消失。这种具有超顺磁性的样品在高温磁传感器的研制中具有潜在的应用价值。
SiCN magnetic ceramics doped with Fe ions were synthesized at different pyrolysis temperatures in the range from 600 to 1600A degrees C. Several phases of ceramics were detected using the techniques of electron paramagnetic resonance/ferromagnetic resonance, Raman, Fourier-transform infrared and X-ray diffractometry, listed as follows: (a) transformation to the ceramic state from the polymer state, where the Fe ions are in the paramagnetic state, as the temperature is increased from 600 to 800A degrees C; (b) formation of two different Fe species in the range of 950-1150A degrees C: nanocrystalline particles in the ferromagnetic state and Fe ions incorporated into the free-carbon state in the superparamagnetic state; (c) diminution of the free-carbon content above 1150A degrees C, and, as a consequence, diminution of the intensity of the broad Fe signal related to this phase; (d) appearance of a new Fe phase at about 1200A degrees C; (e) disappearance of the ferromagnetic phase at about 1400A degrees C; (f) disappearance of all Fe ions above 1530A degrees C. The samples exhibiting superparamagnetic behavior are potentially useful in developing high-temperature magnetic sensor devices.