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The structure and magnetic properties of (Fe[sub 56]Pt[sub 44])[sub 100-x]N[sub x] alloy films with x=0–15 at. % prepared by rf magnetron sputtering were investigated. Compared to an Fe[sub 56]Pt[sub 44] binary film, (Fe[sub 56]Pt[sub 44])[sub 100-x]N[sub x] alloy films showed great enhancement in hard magnetic properties. A coercivity H[sub c] of 1027 kA/m, a remanence M[sub r] of 1.24 T, and a maximum energy product (BH)[sub max] of 260 kJ/m3 were obtained for an (Fe[sub 56]Pt[sub 44])[sub 93]N[sub 7] film annealed at 600 °C for 10 min, whereas the Fe[sub 56]Pt[sub 44] film annealed at the same conditions gave H[sub c]=682 kA/m, M[sub r]=0.87 T, and (BH)[sub max]=132 kJ/m[sup 3]. Structural analysis revealed that N addition influenced the phase structure and microstructure of FePt films. N atoms incorporated in the disordered FePt phase in as-deposited films, they released rapidly out of the FePt phase by vacuum annealing. It is suggested that the rapid release of N atoms from the FePt phase promotes the transformation to the ordered phase, results in a higher coercivity of the film. The high remanence of the (Fe[sub 56]Pt[sub 44])[sub 93]N[sub 7] film is attributed to enhanced exchange coupling of the soft iron nitride phase and the hard FePt phase. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract: Gas exchange and chlorophyll fluorescence quenching analysis were carried out to investigate the diurnal variations in photosynthesis and light allocation in leaves of soybean. Leaf net CO2 assimilation rate showed a bimodal diurnal pattern and midday depression of CO2 assimilation was observed at 13:00h. Depression in CO2 assimilation at midday was mostly attributed to non-stomatal limitation since the reduction in net CO2 assimilation rate was not followed by significant reductions in stomatal conductance and intracellular CO2 concentration. Midday depression in CO2 assimilation was found to be associated with reversible inactivation of photosystem II reaction centers and increases of antenna heat dissipation and photorespiration in response to the high light intensity. It is likely that PS II down-regulation, heat dissipation and photorespiration co-operated together to prevent the chloroplast from photodamage. [Copyright &y& Elsevier]

The structure influence of carbon atoms in RFe10.5Mo1.5Cx (R=Nd, Y, Dy) compounds was investigated by using X-ray diffraction. A detailed 57Fe Mo¨ssbauer spectroscopy under 77 K and hyperfine field interaction are presented. The studies indicate that the incorporation of carbon atoms into its parent compound can increase the hyperfine field and the saturation magnetization. The result confirmed that the magnetic properties of RFe10.5Mo1.5 compounds can be improved by interstitial carbon atoms just like the influence of nitrogen atoms. [Copyright &y& Elsevier]