More Supriya, Raut Suyog, Premkumar S, Bhopale Somnath, Bhoraskar Sudha, More Mahendra, Mathe Vikas
Department of Physics, Savitribai Phule Pune University Ganeshkhind Pune 411007 Maharashtra India
Armament Research and Development Establishment Pune 411021 Maharashtra India.
RSC Adv. 2020 Aug 28;10(53):32088-32101. doi: 10.1039/d0ra05410k. eCollection 2020 Aug 26.
The work presented involves the generation of oxygen plasma species at low pressure utilizing an Electron Cyclotron Resonance (ECR) plasma reactor, and their interactions with micron- and nano-sized iron films (M-Fe and N-Fe film respectively) prepared using ethyl cellulose processed at high temperature. A specially designed radiation heater (RH) was used to raise the surface temperature of the film rapidly, exactly at the film interface, where the plasma species interact with the surface. As a result of the interaction of oxygen plasma species and temperature, iron is oxidized to different polymorphs depending on the operating pressure and hence oxygen gas flow rate. The phase, as well as the morphology of the film was controlled by monitoring the oxygen flow rate using the unique Plasma-Assisted Thermal Oxidation (PATO) process. Different polymorphs, , FeO, γ-FeO, α-FeO and different morphologies, such as polygonal, compact facets, wire-like (1D) nanostructures at the surface were obtained for the films processed using PATO. The selected PATO-processed films were investigated for Field Electron Emission (FEE) properties. The 1D-grown surface of iron oxide obtained from the M-Fe film showed a turn-on field of 3 MV m and emission current of 337 μA cm, whereas the pyramidal surface morphology obtained using N-Fe film gives a turn-on field of 3.3 MV m with an emission current of 578 μA cm.
所展示的工作涉及利用电子回旋共振（ECR）等离子体反应器在低压下产生氧等离子体物种，以及它们与使用高温处理的乙基纤维素制备的微米级和纳米级铁膜（分别为M-Fe和N-Fe膜）的相互作用。使用专门设计的辐射加热器（RH）在膜界面处迅速提高膜的表面温度，膜界面正是等离子体物种与表面相互作用的地方。由于氧等离子体物种与温度的相互作用，根据操作压力以及因此的氧气流量，铁被氧化成不同的多晶型物。通过使用独特的等离子体辅助热氧化（PATO）工艺监测氧气流量，可控制膜的相以及形态。对于使用PATO工艺处理的膜，获得了不同的多晶型物，如FeO、γ-FeO、α-FeO以及不同的形态，例如表面的多边形、致密小面、线状（一维）纳米结构。对选定的经PATO处理的膜进行了场电子发射（FEE）特性研究。从M-Fe膜获得的一维生长的氧化铁表面显示出3 MV m的开启场和337 μA cm的发射电流，而使用N-Fe膜获得的金字塔形表面形态给出了3.3 MV m的开启场和578 μA cm的发射电流。
