Mn掺杂SiC磁性薄膜的结构表征

Structural characterization of Mn doped SiC magnetic thin films

利用反射式高能电子衍射(RHEED)、X射线衍射(XRD)和X射线吸收近边结构谱(XANES)等技术研究了在950℃条件下Si(111)衬底上共蒸发分子束外延方法制备的Mn掺杂SiC磁性薄膜的结构特征.RHEED结果表明,生长的Mn掺杂SiC薄膜为立方结构.XRD和XANES结果表明,在Mn掺杂量为0.5%和18%的样品中,Mn原子均是与SiC半导体介质中的Si原子反应生成镶嵌在SiC基体中的Mn4Si7化合物颗粒,并未观察到在SiC晶格中有替代式或间隙式的Mn原子存在.认为Mn掺杂SiC薄膜的铁磁性主要来源于Mn4Si7纳米晶第二相.

Mn-doped SiC magnetic thin films prepared by co-deposited molecular beam epitaxy（MBE） method on Si（111） substrates at 950 ℃ have been investigated by reflection high energy diffraction（RHEED）,X-ray diffraction（XRD） and X-ray absorption near edge structure（XANES） techniques.RHEED results reveal that the SiC thin films doped with Mn are of the cubic structure.XRD and XANES results show that in the thin films with Mn doping concentrations of 0.5% and 18%,almost all the Mn atoms react with Si atoms,forming Mn4Si7 compound embedded in the SiC matrix,and no substitutional or interstitial Mn atoms exist in the SiC lattice.Furthermore,we hold that the ferromagnetism of the Mn doped SiC thin films originates mainly from the Mn4Si7 secondary phase.