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CoFe/Si interfacial structures have been realised by electron beam evaporation of CoFe magnetic alloy on p- and n-Si substrates. These realised interfacial structures have been characterised from X-ray diffraction (XRD), atomic force microscopy (AFM), magnetic force microscopy (MFM) and magnetisation (M–H) characteristics. XRD data have shown the presence of CoFe (bcc phase) and β-FeSi2phases for CoFe/p-Si interfacial structures, whereas CoFe/n-Si interfacial structures have shown the presence of CoFe (bcc and fcc) phases along with Fe3Si, ϵ-FeSi and β-FeSi2silicide phases having nanodimension crystallites. TheM–Hcharacteristics have shown the superparamagnetic type behaviour for CoFe/p-Si structure, whereas CoFe/n-Si structure shows a feature of interfacial antiferromagnetic (AF) coupling. The observed magnetic behaviour has been understood due to the presence of various magnetic phases and their nanosized grains. The MFM data of domain size have also been correlated with the observed magnetic behaviour. CoFe/n-Si structures have shown a significant feature of giant magnetoresistance (GMR) as compared to CoFe/p-Si structures. It has been found that CoFe/p-Si structures show a distinctly different behaviour than CoFe/n-Si structures for their chemical structure, morphology and magnetic behaviour. [ABSTRACT FROM AUTHOR]

An experiment was conducted with iron chlorosis affected low-chill peach cultivars such as ‘Shaharanpur Prabhat’, ‘Shan-e-Punjab’, and ‘Pratap’ to examine the recovery upon foliar application of three iron sources namely iron (Fe)-sulfate, Fe-citrate and Fe ethylenediaminetetraacetic acid (EDTA). All the iron sources significantly increased the SPAD meter value, physiologically active (Fe2+) iron and total iron content of the leaves over control. However, highest values were noted with foliar spray of 1.0% Fe-sulfate. The low-chill peach cultivar ‘Saharanpur Prabhat’ responded best with iron resupply treatment. Significant correlations (atP≤ 0.01) were obtained between SPAD meter readings with both physiologically active iron (Fe2+) and total iron content of leaves in all peach cultivars. Among the sources, the correlations between SPAD meter readings, physiologically active iron (Fe2+) and total iron contents were significant atP≤ 0.01 for only Fe-sulfate and Fe-citrate. The regression analysis showed that the SPAD meter reading accounted 78.2 to 88.0% variation in physiologically active iron (Fe2+) and 65.0 to 73.7% variation in the total iron content in the low-chill peach cultivars. The SPAD readings could be used for management of iron chlorosis in peach orchard. [ABSTRACT FROM PUBLISHER]

□ Phosphorus enriched post-methanation biosludges (PEMB) from molasses-based distilleries have been developed and evaluated as phosphorus (P) sources for rice-wheat rotation under field condition in a Mollisol. Chemical speciation of P and calcium (Ca) in the aqueous solution of these new P sources PEMB 1 (5.1% P) and PEMB 2 (7.61% P) revealed that a higher proportion of soluble Ca in single superphosphate (SSP) existed as free Ca2+while it was complexed by dissolved organic carbon in both PEMB 1 and PEMB 2. In the field experiment, application of PEMB 2 at 16.5 kg P ha−1resulted in either statistically similar or higher grain yields and total P uptake in both rice and wheat crops than with SSP applied at 22.0 kg P ha−1. Mean apparent P recovery values with PEMB 2 were higher than the respective values observed with PEMB 1 or with SSP applied at 22.0 kg P ha−1. [ABSTRACT FROM AUTHOR]

A greenhouse experiment was conducted to evaluate the critical toxic limits of nickel (Ni) in french bean grown on a mollisol receiving varying levels of farmyard manure (FYM). Nickel levels beyond 10 mg kg−1 soil brought a significant reduction in the dry matter yields of french bean. Application of FYM, especially at the higher level (4.46 g kg−1 soil), had a favorable effect on the dry matter yields of french bean. The effect of FYM application was more pronounced at the medium levels of Ni. Application of higher level of FYM could decrease Ni concentration in plants significantly. Different soil extractants employed in the present study could be arranged in the following order of their Ni extraction power: Mehlich 3 > 0.1 N hydrochloric acid (HCl) > double acid > ammonium bicarbonate (AB)-diethylenetriaminepentaacetic acid (DTPA) > DTPA. Among different extractants evaluated in the study, DTPA (pH 7.3) appeared to be most promising for predicting Ni concentration in french bean. The threshold toxic levels of Ni in french bean and also in terms of extractable soil Ni contents were influenced by FYM application. [ABSTRACT FROM PUBLISHER]

Abstract: In this work we report on swift heavy ion irradiation induced nano granular magnetic metallic Fe5Si3 silicide phase formation due to strong interfacial intermixing in Fe/Si bilayer samples. The bilayer samples have been irradiated with swift (100MeV) heavy (56Fe7+) ions having a fluence of 1×1014 ionscm−2. It has been found that swift heavy ion causes strong irradiation induced interfacial intermixing and forms nano granular magnetic metallic Fe5Si3 silicide in Fe/Si bilayer samples, which shows strong uniform magnetic interaction and interacting magnetic particle behaviour at room temperature (RT). [Copyright &y& Elsevier]

In a greenhouse experiment, involving factorial combinations of nitrogen (N) (0, 15, 30, 45, and 60 mg kg- 1 soil) and sulfur (S) (0, 7.5, 15.0, 22.5, 30.0 mg kg- 1soil), application of all levels of N and S 15 mg kg- 1 and above increased the grain yield of aromatic rice (Basmati cv. 'Taraori') significantly. The highest grain yield of aromatic rice was recorded from the treatment combinations of 60 mg N + 15 mg S kg- 1 or 45 mg N + 30 mg S kg- 1. The interaction of N and S influenced the N and S content in rice grain, N content in straw, N: S ratio both in grain and straw, milling (%), and other quality parameters significantly. Milling (%) and hulling (%), thousand grain weight, L: B ratio, cooked grain breadth, and aroma score were found to be significantly and positively correlated with the N: S ratio of rice grain while grain breadth had a significant inverse relationship with N: S ratio in grain. [ABSTRACT FROM AUTHOR]

Abstract: A study on irradiation (of ∼100MeV, Si-ion) induced degradation effects of crystalline silicon solar cells has been carried out. The cell characteristics show that the cell efficiency decreases to ∼30% (of its pre-irradiated value) after the irradiation (of swift heavy ions of, 1012 or 1013 or 1014 ionscm−2 fluences). The reduced efficiency of the irradiated solar cells is recovered back (nearly half of the pre-irradiated efficiency) after annealing at 300°C. The IR spectroscopic studies on the irradiated and annealed solar cells show the presence of di-vacancy and their complexes with impurities like hydrogen, carbon and oxygen. The swift heavy ion irradiation damage in solar cells causing a heavy loss of the cell efficiency has been attributed to these electrically active complexes which shall cause the carrier removal/compensation phenomena for the observed decrease of the cell efficiency. These complexes dissociate on annealing to change their role as donors/acceptors to cause the observed recovery of the cell efficiency on annealing. [Copyright &y& Elsevier]

Surface modifications caused by a swift heavy ion irradiation on a crystalline p-type silicon crystal have been reported. ∼100 MeV Si7+ ions from a 15UD Pelletron source has been employed with varying fluence of 1012 and 1013 ions cm-2. Atomic force microscopy has been extensively used to study these surface modifications. Significant observation includes the evidence for a plastic flow upon irradiation. Attempts have been made to explain the results on the basis of radiation-induced amorphization followed by recrystallization. The observation confirms the occurrence of these types of effects in such irradiations and is in line with the models based on thermal spike approach. [Copyright &y& Elsevier]

The p-silicon surfaces have been irradiated with ~ 100 MeV Si7+ions to a fluence of 2.2×1013 ions cm-2, and surface morphology has been studied with atomic force microscopy (AFM). Interesting features of cracks of ~ 47 nm in depth and ~ 103 nm in width on the irradiated surfaces have been observed. The observed features seemed to have been caused by the irradiation-induced stress in the irradiated regions of the target surface. [ABSTRACT FROM AUTHOR]

Examines the different forms and quantity-intensity (Q/I) parameters of potassium (K) in some soil samples from several districts of Sikkim, India. Number if surface soil samples collected from the districts; Range and mean values of soil pH, organic matter and different forms of K in the samples; Data on the correlation coefficients between Q/I parameters and different K forms.

Studies the frequency-dependent current-voltage characteristics of water treated Al/Si(n) junctions. Preparation of Al/Si interfaces; Extrinsic interface state capacitance at the Al/Si interface; Quantitative estimation of the density of states, energies in the forbidden gap of the semiconductors and capture cross-section for the states; Charge exchange between the interface states and the conduction band.

Oxide layers of thicknesses less than 100A have been prepared by thermaloxidation of a base metal electrode film of aluminium. These films were then neutron-irradiated from a laboratory Ra—Be source to a fluence of ∼l0[sup 11] neutrons em[sup -2] and the sandwich structure, Al-Al[sub 2]O[sub 3]. Au, was completed by depositing a thin metal film of gold over the irradiated oxide layer. D.C. steady and transient flow through the sandwich structures have been studied. Results obtained in our experiments with irradiated sandwiches have been compared with unirradiated ones to show that traps are introduced because of the damage caused by the incident neutrons. Transient voltage measurement across the junction gives a trap density of ∼ 10[sup 18] cm[sup -3]. A capture cross-section of the order l0[sup -28]cm² is estimated for the traps. It is found that the (identified) traps are uniformly distributed within an energy of 0.099 eV below the conduction band edge of aluminium oxide. The physical nature of the traps is dismissed by comparing the capture crosssections of the physically known trapping centres. The possibility of vacancies or F-centres acting as traps (for the identified ones) has been suggested. [ABSTRACT FROM AUTHOR]

Electron transport mechanisms for current flow in very thin (about 50 Å) A1[sub 2]O[sub 3] sandwiched film has been studied. At low voltages a tunnelling mechanism has been proposed and at higher voltages Scottky and space-charge mechanisms are reported. The mechanisms of conduction have been explained on the basis of different current voltage and current-temperature curves. [ABSTRACT FROM AUTHOR]