Photoemission Studies of K-Promoted Nitridation of InP (100) Surface Using Synchrotron Radiation

The effect of molecular nitrogen exposure on the surfaces of InP(100)modified by potassium overlayers is investigated by core-level and valence-band photoemission spectroscopy using Synchrotron radiation.In comparison with InP(110)surface,we found the promotion is much stronger for InP(100)surface due to the central role of surface defects in the promotion;furthermore,in contrast with K-promoted oxidation of InP(100)where the bonding is observed between indium and oxygen,indium atoms did not react directly with nitrogen atoms during the K-promoted nitridation of InP(100).

Electronic Structure in Cd_(0.96)Zn_(0.04)Te Compound: A Synchrotron Radiation Photoemission Study

We have studied the electronic structure of clean CdZnTe(111)compound using high resolution synchrotron radiation photoemission spectroscopy.Surface states were found in Cd,Te 4d core levels and valence band.The valence band measurement is in good agreement with theoretical calculations using linear muffin-tin orbit method.

The spin and orbital moment contributions of each element to macroscopic magnetization in Co_(0.9)Fe_(0.1) films

Co-Fe alloy films have such properties as high saturation magnetization, high Curie tem- perature and low coercive force. It is of importance to study the origin of high saturation magnetization in these alloys. In this paper, we study the spin (ms) and orbital moments (mo) of Fe and Co in the Co0.9Fe0.1 film by using X-ray magnetic circular dichroism (XMCD) and SQUID magnetometry. The ms and mo for Co are 1.58 and 0.31 μB, and for Fe are 1.63 and 0.36 μB respectively. The average magnetic moment (1.90 μB) determined by XMCD is in agreement with that obtained from SQUID measurements. The total magnetic moment ratio of Fe to Co is 10.5:89.5, while the ratio of the spin to orbital moment is 83.4:16.6. Considering the separation of the spin and orbital moment, an outcome of mFe-spin : mFe-orbit : mCo-spin : mCo-orbit = 8.6:1.9:74.8:14.7 is obtained.

Impact of the CoFe microstructure etched surface oxidation on Co spin and orbital moment

Patterned ferromagnetic thin film shows promising applications in ultra-high density magnetic storage,magnetoresistive transducer,magnetic random access memory and many other devices.Since the performance of these devices is closely associated with the magnetic properties of the etched patterns,it is necessary to study the effects of freshly etched surface oxidation on the magnetic properties of the patterned microstructures.In the current work,were carried out an X-ray Magnetic Circular Dichroism(XMCD) study on a 50 nm Co 0.9 Fe 0.1 continuous thin film and a related patterned Co 0.9 Fe 0.1 grating structure etched with a 2 μm period.Based on the sum rules,the spin and orbital moments were calculated for these two samples,respectively.The results indicated that the spin and orbital moments of grating structure(1.34μ B and 0.24μ B,respectively) decreased 17.3% compared with the corresponding continuous film(1.62μ B and 0.29μ B,respectively).We proposed that the moment decreasing of the patterned grating structure was mainly caused by the etched surface oxidation during the pattern manufacture process.The oxidation ratio of Co element in the patterned grating structure is 14.4% calculated from X-ray absorption spectroscopy(XAS) measurement.Considering the oxidation ratio,we amend the spin and orbital moment of Co and the amended result is basically in accordance with that of continuous film,demonstrating that the difference of the spin and orbital moments between the sub-micron grating unit and the continuous film is really caused by the oxidation.