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103. THEORY OF MEDIUM-RANK 2ND-ORDER CALIBRATION WITH RESTRICTED-TUCKER MODELS

Author

Smilde, A. K., WANG, Y. D., KOWALSKI, B. R., and Other departments

Abstract

If an analytical instrument or instrumental method gives a response matrix when analyzing a pure analyte, the instrument or instrumental method is called a second-order method. Second-order methods that generate a response matrix for a pure analyte of rank one are called rank-one second-order methods. If the response matrix of a pure analyte is not rank one, essentially two cases exist: medium rank (between two and five) and high rank (greater than five). Subsequently, medium- and high-rank second-order calibration tries to use medium- and high-rank second-order methods to analyze for analytes of interest in a mixture. A particular advantage of second-order methods is the ability to analyze for analytes of interest in a mixture which contains unknown interferences. Keeping this advantage is the challenge on moving away from rank-one second-order calibration methods. In this paper a medium-rank second-order calibration method is proposed based on least-squares restricted Tucker models. With this method the second-order advantage is retained

Published
1994

104. MULTICOMPONENT DETERMINATION OF CHLORINATED HYDROCARBONS USING A REACTION-BASED CHEMICAL SENSOR .3. MEDIUM-RANK 2ND-ORDER CALIBRATION WITH RESTRICTED TUCKER MODELS

Author

Smilde, A. K., Tauler, R., HENSHAW, J. M., BURGESS, L. W., KOWALSKI, B. R., and Other departments

Abstract

The calibration of a chemical sensor for chlorinated hydrocarbon analytes based on the Fujiwara reaction is described. This sensor generates a particular type of data: medium-rank second-order data. With this type of data it is possible to calibrate the sensor in such a way that quantitation for the analytes in the presence of unknown interferents is possible. The calibration method developed is a new approach based on so-called restricted Tucker models that utilize all available chemical information

Published
1994

105. Magnetism and magnetotransport of strongly disordered Zn1−xMnxGeAs2 semiconductor: The role of nanoscale magnetic clusters

Author

Kilanski, L., primary, Górska, M., additional, Dobrowolski, W., additional, Dynowska, E., additional, Wójcik, M., additional, Kowalski, B. J., additional, Anderson, J. R., additional, Rotundu, C. R., additional, Maude, D. K., additional, Varnavskiy, S. A., additional, Fedorchenko, I. V., additional, and Marenkin, S. F., additional

Published
2010
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110. Resonant photoemission studies of Gd/PbGdTe

Author

Pietrzyk, M A, primary, Orlowski, B A, additional, Kowalski, B J, additional, Dziawa, P, additional, Osinniy, V, additional, Story, T, additional, Taliashvili, B, additional, and Johnson, R L, additional

Published
2008
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112. MnAsdots grown onGaN(0001¯)−(1×1)surface

Author

Kowalik, I. A., primary, Kowalski, B. J., additional, Iwanowski, R. J., additional, Kopalko, K., additional, Łusakowska, E., additional, Sawicki, M., additional, Sadowski, J., additional, Adell, M., additional, Grzegory, I., additional, and Porowski, S., additional

Published
2007
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116. Magnetic Order and Magnetic Inhomogeneities in SnCrTe-PbCrTe Solid Solutions.

Author

Kilanski, L., Szymański, M., Brodowska, B., Górska, M., Szymczak, R., Podgórni, A., Avdonin, A., Reszka, A., Kowalski, B. J., Domukhovski, V., Arciszewska, M., Dobrowolski, W., Slynko, V. E., and Slynko, E. I.

Subjects
MAGNETIC properties, FERROMAGNETIC materials, CRYSTALLIZATION, SOLIDIFICATION, GEOCHEMISTRY
Abstract

We present the studies of structural, electrical and magnetic properties of bulk Sn1−x−y PbxCryTe mixed crystals with chemical composition 0.18 ⩽ x ⩽ 0.35 and 0.007 ⩽ y ⩽ 0.071. The magnetometric studies indicate that for the high Cr-content, y = 0.071, the alloy shows ferromagnetic alignment with the Curie temperature, TC, around 265 K. The Cr5Te8 clusters are responsible for the ferromagnetic order. At low Cr content, y = 0.01, a peak in the ac magnetic susceptibility identified as the cluster-glass-like transition is observed at a temperature about 130 K. The cluster-glass-like transition is likely due to the presence of Cr2Te3 clusters in the samples with y ≈ 0.01. The transport characterization of the samples indicated strong metallic p-type conductivity with relatively high carrier concentration, n > 1020 cm−3, and carrier mobility, μ > 150 cm2/(V s). [ABSTRACT FROM AUTHOR]

Published
2014
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117. Swift Xe26+ Ion Irradiation Effect on Luminescent Properties of Undoped and Cd-Doped ZnO Films.

Author

Myroniuk, D. V., Lashkarev, G. V., Shtepliuk, I. I., Skuratov, V. A., Reszka, A., and Kowalski, B. J.

Subjects
MAGNETRONS, RADIO frequency, CADMIUM, IRRADIATION, PHOSPHORS
Abstract

Here we report the effect of the irradiation by 167 MeV Xe26+ ions (in the fluence range up to 3×1012 ions/cm2) on the undoped and Cd-doped (0.4, 0.5 at.%) ZnO films deposited by radiofrequency magnetron sputtering. As-grown and irradiated samples were investigated by cathodoluminescence spectroscopy. It was found that the radiation causes a decrease in intensity of luminescent peaks and a redistribution of the radiative recombination channels. We revealed that the cadmium incorporation into ZnO lattice enhances the radiation resistance of ZnO film. [ABSTRACT FROM AUTHOR]

Published
2014
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118. Anomalous Hall Effect in Ge1-x-yPbxMnyTe Composite System.

Author

Podgórni, A., Kilanski, L., Dobrowolski, W., Górska, M., Domukhovski, V., Brodowska, B., Reszka, A., Kowalski, B. J., Slynko, V. E., and Slynko, E. I.

Subjects
ANOMALOUS Hall effect, HALL effect devices, GALVANOMAGNETIC effects, GYRATORS, HALL effect
Abstract

The purpose of this study was to investigate the magnetotransport properties of the Ge0.743Pb0.183Mn0.074Te mixed crystal. The results of magnetization measurements indicated that the compound is a spin-glass-like diluted magnetic semiconductor with critical temperature TSG = 97.5 K. Nanoclusters in the sample are observed. Both, matrix and clusters are magnetically active. Resistivity as a function of temperature has a minimum at 30 K. Below the minimum a variable-range hopping is observed, while above the minimum a metallic-like behavior occurs. The crystal has high hole concentration, p = 6.6×1020 cm-3, temperature-independent. Magnetoresistance amplitude changes from –0.78 to 1.18% with increase of temperature. In the magnetotransport measurements we observed the anomalous Hall effect with hysteresis loops. Calculated anomalous Hall effect coeffcient, RS = 2.0 × 106 m3/C, is temperature independent. The analysis indicates the extrinsic skew scattering mechanism to be the main physical mechanism responsible for anomalous Hall effect in Ge0.743Pb0.183Mn0.074Te alloy. [ABSTRACT FROM AUTHOR]

Published
2014
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120. OPTICAL PROPERTIES OF "BLACK SILICON" FOR SOLAR CELLS APPLICATION FORMED BY LASER RADIATION.

Author

Jarimaviciute-Gudaitiene, R., Prosycevas, I., Dauksta, E., Onufrijevs, P., Medvids, A., and Kowalski, B.

Subjects
LASER beams, OPTICAL properties, SOLAR energy, DIRECT energy conversion, SOLAR cells, SILICON
Abstract

In our recent work we have elaborated a new laser method for formation of "black silicon" consisting of micro-cones using Si substrate with or without Ni catalyst. In this paper, we continue to study of structural, optical and chemical properties of the obtained structure. Reflection index of structure depends on shape and height of micro-cone, it means depends on Nd:YAG laser intensity and number of laser pulses. SEM-EDX and photoluminescence methods were used to investigate the "black silicon" structures surface morphology, chemical analysis and optical properties. [ABSTRACT FROM AUTHOR]

Published
2012

126. Reaction of I-2 with the (001) surfaces of GaAs, InAs, and InSb .2. Ordering of the iodine overlayer

Author

Varekamp, P R, Hakansson, M C, Kanski, J, Bjorkqvist, M, Gothelid, M, Kowalski, B J, He, Z Q, Shuh, D K, Yarmoff, J A, Karlsson, Ulf O, Varekamp, P R, Hakansson, M C, Kanski, J, Bjorkqvist, M, Gothelid, M, Kowalski, B J, He, Z Q, Shuh, D K, Yarmoff, J A, and Karlsson, Ulf O

Abstract

The overlayer formed by the reaction of molecular iodine (I-2) with GaAs(001), InAs(001), and InSb(001) is investigated with synchrotron soft x-ray photoelectron spectroscopy (SXPS) and scanning tunneling microscopy (STM). Two components, separated by about 0.5 eV, are present in all of the I 4d SXPS spectra. At very low iodine coverages, the high binding energy (BE) component dominates. When the iodine coverage saturates, however, the two components have equal intensities. In contrast to GaAs and InAs, exposure of InSb(001)-c(8x2) to additional I-2 results in a further increase of the relative intensity of the low-BE component. STM images of I-2 covered InSb(001)-c(8x2) directly reveal the ordering in the overlayer. Islands are visible for submonolayer coverages, suggesting that adsorption occurs via a mobile precursor state. STM images feature occupies a 1x1 unit cell with the same spacing as bulk-terminated InSb(001). The other feature has a coverage of similar to 1/3 ML and is arranged in pairs oriented along the [110] azimuth., NR 20140805

Published
1996
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127. Angle-resolved photoemission spectroscopy of the 1x1 ordered overlayers on iodine-saturated GaAs(001) and InAs(001)

Author

Varekamp, P R, Hakansson, M C, Kanski, J, Kowalski, B J, Olsson, L O, Ilver, L, He, Z Q, Yarmoff, J A, Karlsson, Ulf O, Varekamp, P R, Hakansson, M C, Kanski, J, Kowalski, B J, Olsson, L O, Ilver, L, He, Z Q, Yarmoff, J A, and Karlsson, Ulf O

Abstract

Angle-resolved valence band photoelectron spectra are collected from 1 X 1 ordered overlayers on I-2-saturated GaAs(001)-4 x 1, -c(2 X 8), and InAs(001)-c(8 x 2). A high-intensity dispersive surface state, located approximately 4.4 eV below the valence band maximum, is observed in each case. The state passes through an open lens in the projected bulk density of states and disperses symmetrically around the surface Brillouin zone edge. For all surfaces studied, the state is stronger when excited with the electric field polarized in the [110], as compared to the <(1)over bar 10>], azimuth. Since the state is independent of the termination of the initial surface, and since iodine bonds primarily to the outermost element, the state must result from delocalization of the electron states in the overlayer, and is not related to bonding with the substrate., NR 20140805

Published
1996
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136. Magnetic Properties of Sn1-xCrxTe Diluted Magnetic Semiconductors.

Author

KILANSKI, L., PODGÓRNI, A., GÓRSKA, M., DOBROWOLSKI, W., SLYNKO, V. E., SLYNKO, E. I., RESZKA, A., and KOWALSKI, B. J.

Subjects
MAGNETIC semiconductors, MICROCLUSTERS, MAGNETIC susceptibility, SPIN glasses, GLASS transitions
Abstract

We present the studies of Sn1-xCrxTe semimagnetic semiconductors with chemical composition x ranging from 0.004 to 0.012. The structural characterization indicates that even at low average Cr-content x ⩽ 0:012, the aggregation into micrometer size clusters appears in our samples. The magnetic properties are affected by the presence of clusters. In all our samples we observe the transition into the ordered state at temperatures between 130 and 140 K. The analysis of both static and dynamic magnetic susceptibility data indicates that the spin-glass-like state is observed in our samples. The addition of Cr to the alloy seems to shift the spin-glass-like transition from 130 K for x = 0:004 to 140 K for x = 0:012. [ABSTRACT FROM AUTHOR]

Published
2013
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