低温物理学报
低溫物理學報
저온물이학보
CHINESE JOURNAL OF LOW TEMPERATURE PHYSICS
2002年
4期
254-259
,共6页
我们在真空离子束溅射设备中制备了Co-SiO2颗粒膜.其结构和磁性分别利用透射电子显微术(TEM)和铁磁共振(FMR)来研究.TEM分析表明Co纳米颗粒相互独立地分布在SiO2介质中,且尺寸分布非常窄.室温转角FMR实验显示薄膜具有单轴各向异性.变温FMR实验被用来研究在100~300K温度范围内的颗粒间相互作用强度随温度变化的关系(我们利用一理论模型计算了颗粒集合体中的铁磁部分所占比例和超顺磁部分所占比例).我们发现颗粒间相互作用强度除了与温度有关之外,还与Co颗粒的尺寸直接相关.
我們在真空離子束濺射設備中製備瞭Co-SiO2顆粒膜.其結構和磁性分彆利用透射電子顯微術(TEM)和鐵磁共振(FMR)來研究.TEM分析錶明Co納米顆粒相互獨立地分佈在SiO2介質中,且呎吋分佈非常窄.室溫轉角FMR實驗顯示薄膜具有單軸各嚮異性.變溫FMR實驗被用來研究在100~300K溫度範圍內的顆粒間相互作用彊度隨溫度變化的關繫(我們利用一理論模型計算瞭顆粒集閤體中的鐵磁部分所佔比例和超順磁部分所佔比例).我們髮現顆粒間相互作用彊度除瞭與溫度有關之外,還與Co顆粒的呎吋直接相關.
아문재진공리자속천사설비중제비료Co-SiO2과립막.기결구화자성분별이용투사전자현미술(TEM)화철자공진(FMR)래연구.TEM분석표명Co납미과립상호독입지분포재SiO2개질중,차척촌분포비상착.실온전각FMR실험현시박막구유단축각향이성.변온FMR실험피용래연구재100~300K온도범위내적과립간상호작용강도수온도변화적관계(아문이용일이론모형계산료과립집합체중적철자부분소점비례화초순자부분소점비례).아문발현과립간상호작용강도제료여온도유관지외,환여Co과립적척촌직접상관.
Co-SiO2 magnetic granular films were prepared with ion-sputtering method. Structures and magnetic properties of the films were studied by transmission electron microscopy (TEM) and ferromagnetic resonance (FMR) respectively. TEM analysis reveals that isolated Co nanoparticles disperse in the SiO2 matrix with very narrow size distributions. Angular variational FMR experiments indicate uniaxial anisotropies in the films. The temperature dependence of FMR data is employed to determine the degree of interparticle interactions in a temperature range of 100~300K, ferromagnetic fraction and superparamagnetic fraction are calculated. We find that the degree of interparticle interactions depends not only on the temperature, but also on the size of the Co nanoparticles.