The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

S.s. Major - One of the best experts on this subject based on the ideXlab platform.

  • Effect of heat treatment on the photoluminescence of CdS nanocrystallites in cadmium-rich organic Langmuir Blodgett matrix
    'Elsevier BV', 2013
    Co-Authors: Pavan K. Narayanam, S.s. Talwar, Rs Srinivasa, Soni P, Mohanta P, S.s. Major
    Abstract:

    CdS nanocrystallites were grown within an organic layered matrix by partial sulphidation of precursor cadmium Arachidate LB multilayers. The cadmium Arachidate-arachidic acid composite multilayers containing CdS nanocrystallites were enriched by intercalation with Cd2+ ions in aqueous solution of CdCl2 and subsequently heat treated at different temperatures up to 300 degrees C, in air and in vacuum. CdS nanocrystallites within the composite multilayer have been found to exhibit treatment process dependent characteristic changes in optical absorption and luminescence. The optical data obtained at different stages/conditions of processing have been analyzed by considering changes in excitonic absorption and emission as well as contributions from surface and bulk defects related emission and a suitable energy level diagram has been proposed. The composition, microstructure and surface morphology of the composite multilayers were also studied at all stages of processing to develop a comprehensive understanding of the interaction of the organic matrix with CdS nanocrystallites and the consequent influence on the optical behavior of the nanocrystallites. These studies have shown that the organic moieties encapsulating the CdS nanocrystallites tend to restrict their growth and aggregation, while the presence of cadmium in the organic matrix is responsible for the passivation of surface defects as well as the reduction of bulk defects, and these factors have significant influence on the photoluminescence of CdS nanocrystallites. (C) 2013 Elsevier B.V. All rights reserved

  • Enhanced photoluminescence of CdS nanocrystallites in LB multilayers on aqueous treatment
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011
    Co-Authors: Pavan K. Narayanam, Raman S. Srinivasa, S.s. Talwar, S.s. Major
    Abstract:

    Abstract CdS nanocrystallites were formed within the LB matrix of cadmium Arachidate–arachidic acid composite multilayer by post deposition H 2 S exposure of precursor cadmium Arachidate multilayer. The CdS containing multilayers were subjected to post deposition heat treatment in air in the temperature range of 100–300 °C, either directly after the sulphidation process or after being introduced into an aqueous bath. FT-IR spectroscopy was used to study the chemical changes in composite multilayers at different stages of processing. Optical properties of the CdS nanocrystallites were studied by UV–VIS absorption and photoluminescence measurements. A strong enhancement of excitonic emission and suppression of surface states emission from CdS nanocrystallites was observed after heat treatment at 100–150 °C in the case of aqueous treated composite multilayer. X ray reflection and atomic force microscopy show that the aqueous treatment results in expulsion of arachidic acid to the surface of the multilayer resulting in its facile removal during heat treatment. These results suggest that the response to heat treatment of the composite multilayer containing CdS nanocrystallites depends critically on the proximity and access of the unreacted cadmium Arachidate to CdS nanocrystallites. This in turn, provides Cd ions for the passivation of Cd vacancies on the surface of nanocrystallites resulting in a strong enhancement of excitonic emission. Heat treatment at higher temperatures results in drastic reduction of photoluminescence, due to particle growth as well as removal of organic moieties.

  • Enhanced photoluminescence of CdS nanocrystallites in LB multilayers on aqueous treatment
    'Elsevier BV', 2011
    Co-Authors: Pavan K. Narayanam, S.s. Talwar, Rs Srinivasa, S.s. Major
    Abstract:

    CdS nanocrystallites were formed within the LB matrix of cadmium Arachidate-arachidic acid composite multilayer by post deposition H(2)S exposure of precursor cadmium Arachidate multilayer. The CdS containing multilayers were subjected to post deposition heat treatment in air in the temperature range of 100-300 degrees C. either directly after the sulphidation process or after being introduced into an aqueous bath. FT-IR spectroscopy was used to study the chemical changes in composite multilayers at different stages of processing. Optical properties of the CdS nanocrystallites were studied by UV-VIS absorption and photoluminescence measurements. A strong enhancement of excitonic emission and suppression of surface states emission from CdS nanocrystallites was observed after heat treatment at 100-150 degrees C in the case of aqueous treated composite multilayer. X ray reflection and atomic force microscopy show that the aqueous treatment results in expulsion of arachidic acid to the surface of the multilayer resulting in its facile removal during heat treatment. These results suggest that the response to heat treatment of the composite multilayer containing CdS nanocrystallites depends critically on the proximity and access of the unreacted cadmium Arachidate to CdS nanocrystallites. This in turn, provides Cd ions for the passivation of Cd vacancies on the surface of nanocrystallites resulting in a strong enhancement of excitonic emission. Heat treatment at higher temperatures results in drastic reduction of photoluminescence, due to particle growth as well as removal of organic moieties. (C) 2011 Elsevier B.V. All rights reserved

  • Orange-red luminescence from Cu doped CdS nanophosphor prepared using mixed Langmuir-Blodgett multilayers
    'AIP Publishing', 2008
    Co-Authors: Mandal P, S.s. Talwar, S.s. Major, Rs Srinivasa
    Abstract:

    Cu doped CdS nanophosphors were fabricated through Langmuir-Blodgett route for the first time. Precursors mixed Langmuir-Blodgett multilayers of cadmium Arachidate-copper Arachidate were used to grow doped sulfide nanoparticles within the organic matrix through postdeposition treatment with H(2)S gas. Changes in composition and layered structure of precursor multilayers were studied using Fourier transform infrared and x-ray reflection. Uptake of Cu in the multilayers was analyzed by inductively coupled plasma atomic emission spectroscopy measurements. Unannealed H(2)S exposed multilayers containing CdS nanoparticles show strong surface state emission centeredat similar to 570 nm, whereas Cu doped CdS nanoparticles show orange-red luminescence. Photoluminescence (PL) spectra of annealed-Cu doped CdS nanoparticles show distinct Cu-related emission compared to annealed-undoped CdS nanoparticles. Power dependent PL measurements of annealed samples show that an efficient carrier recombination takes place at T(2) level of Cu(++). The carrier relaxation from the excitonic states to T(2) level results in the strong orange-red luminescence

  • ZnO and Zn1-xCdxO nanocrystallites obtained by oxidation of precursor Langmuir-Blodgett multilayers
    'Elsevier BV', 2007
    Co-Authors: Singh Sukhvinder, S.s. Talwar, Rs Srinivasa, S.s. Major
    Abstract:

    ZnO and Zn1−xCdxO nanocrystallites were prepared by oxidation of zinc Arachidate–arachidic acid and zinc Arachidate–cadmium Arachidate–arachidic acid LB multilayers, respectively. The metal content of the multilayers was controlled by manipulation of subphase composition and pH. Precursor multilayers were oxidized in the temperature range of 400 °C–700 °C. The formation of ZnO and Zn1−xCdxO was confirmed by UV–Visible spectroscopy. Uniformly distributed, isolated and nearly mono-dispersed nanocrystallites of ZnO (11 ± 3 nm) and Zn1−xCdxO (18 ± 6 nm) were obtained.© Elsevie

S.s. Talwar - One of the best experts on this subject based on the ideXlab platform.

  • Effect of heat treatment on the photoluminescence of CdS nanocrystallites in cadmium-rich organic Langmuir Blodgett matrix
    'Elsevier BV', 2013
    Co-Authors: Pavan K. Narayanam, S.s. Talwar, Rs Srinivasa, Soni P, Mohanta P, S.s. Major
    Abstract:

    CdS nanocrystallites were grown within an organic layered matrix by partial sulphidation of precursor cadmium Arachidate LB multilayers. The cadmium Arachidate-arachidic acid composite multilayers containing CdS nanocrystallites were enriched by intercalation with Cd2+ ions in aqueous solution of CdCl2 and subsequently heat treated at different temperatures up to 300 degrees C, in air and in vacuum. CdS nanocrystallites within the composite multilayer have been found to exhibit treatment process dependent characteristic changes in optical absorption and luminescence. The optical data obtained at different stages/conditions of processing have been analyzed by considering changes in excitonic absorption and emission as well as contributions from surface and bulk defects related emission and a suitable energy level diagram has been proposed. The composition, microstructure and surface morphology of the composite multilayers were also studied at all stages of processing to develop a comprehensive understanding of the interaction of the organic matrix with CdS nanocrystallites and the consequent influence on the optical behavior of the nanocrystallites. These studies have shown that the organic moieties encapsulating the CdS nanocrystallites tend to restrict their growth and aggregation, while the presence of cadmium in the organic matrix is responsible for the passivation of surface defects as well as the reduction of bulk defects, and these factors have significant influence on the photoluminescence of CdS nanocrystallites. (C) 2013 Elsevier B.V. All rights reserved

  • Enhanced photoluminescence of CdS nanocrystallites in LB multilayers on aqueous treatment
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011
    Co-Authors: Pavan K. Narayanam, Raman S. Srinivasa, S.s. Talwar, S.s. Major
    Abstract:

    Abstract CdS nanocrystallites were formed within the LB matrix of cadmium Arachidate–arachidic acid composite multilayer by post deposition H 2 S exposure of precursor cadmium Arachidate multilayer. The CdS containing multilayers were subjected to post deposition heat treatment in air in the temperature range of 100–300 °C, either directly after the sulphidation process or after being introduced into an aqueous bath. FT-IR spectroscopy was used to study the chemical changes in composite multilayers at different stages of processing. Optical properties of the CdS nanocrystallites were studied by UV–VIS absorption and photoluminescence measurements. A strong enhancement of excitonic emission and suppression of surface states emission from CdS nanocrystallites was observed after heat treatment at 100–150 °C in the case of aqueous treated composite multilayer. X ray reflection and atomic force microscopy show that the aqueous treatment results in expulsion of arachidic acid to the surface of the multilayer resulting in its facile removal during heat treatment. These results suggest that the response to heat treatment of the composite multilayer containing CdS nanocrystallites depends critically on the proximity and access of the unreacted cadmium Arachidate to CdS nanocrystallites. This in turn, provides Cd ions for the passivation of Cd vacancies on the surface of nanocrystallites resulting in a strong enhancement of excitonic emission. Heat treatment at higher temperatures results in drastic reduction of photoluminescence, due to particle growth as well as removal of organic moieties.

  • Enhanced photoluminescence of CdS nanocrystallites in LB multilayers on aqueous treatment
    'Elsevier BV', 2011
    Co-Authors: Pavan K. Narayanam, S.s. Talwar, Rs Srinivasa, S.s. Major
    Abstract:

    CdS nanocrystallites were formed within the LB matrix of cadmium Arachidate-arachidic acid composite multilayer by post deposition H(2)S exposure of precursor cadmium Arachidate multilayer. The CdS containing multilayers were subjected to post deposition heat treatment in air in the temperature range of 100-300 degrees C. either directly after the sulphidation process or after being introduced into an aqueous bath. FT-IR spectroscopy was used to study the chemical changes in composite multilayers at different stages of processing. Optical properties of the CdS nanocrystallites were studied by UV-VIS absorption and photoluminescence measurements. A strong enhancement of excitonic emission and suppression of surface states emission from CdS nanocrystallites was observed after heat treatment at 100-150 degrees C in the case of aqueous treated composite multilayer. X ray reflection and atomic force microscopy show that the aqueous treatment results in expulsion of arachidic acid to the surface of the multilayer resulting in its facile removal during heat treatment. These results suggest that the response to heat treatment of the composite multilayer containing CdS nanocrystallites depends critically on the proximity and access of the unreacted cadmium Arachidate to CdS nanocrystallites. This in turn, provides Cd ions for the passivation of Cd vacancies on the surface of nanocrystallites resulting in a strong enhancement of excitonic emission. Heat treatment at higher temperatures results in drastic reduction of photoluminescence, due to particle growth as well as removal of organic moieties. (C) 2011 Elsevier B.V. All rights reserved

  • Orange-red luminescence from Cu doped CdS nanophosphor prepared using mixed Langmuir-Blodgett multilayers
    'AIP Publishing', 2008
    Co-Authors: Mandal P, S.s. Talwar, S.s. Major, Rs Srinivasa
    Abstract:

    Cu doped CdS nanophosphors were fabricated through Langmuir-Blodgett route for the first time. Precursors mixed Langmuir-Blodgett multilayers of cadmium Arachidate-copper Arachidate were used to grow doped sulfide nanoparticles within the organic matrix through postdeposition treatment with H(2)S gas. Changes in composition and layered structure of precursor multilayers were studied using Fourier transform infrared and x-ray reflection. Uptake of Cu in the multilayers was analyzed by inductively coupled plasma atomic emission spectroscopy measurements. Unannealed H(2)S exposed multilayers containing CdS nanoparticles show strong surface state emission centeredat similar to 570 nm, whereas Cu doped CdS nanoparticles show orange-red luminescence. Photoluminescence (PL) spectra of annealed-Cu doped CdS nanoparticles show distinct Cu-related emission compared to annealed-undoped CdS nanoparticles. Power dependent PL measurements of annealed samples show that an efficient carrier recombination takes place at T(2) level of Cu(++). The carrier relaxation from the excitonic states to T(2) level results in the strong orange-red luminescence

  • ZnO and Zn1-xCdxO nanocrystallites obtained by oxidation of precursor Langmuir-Blodgett multilayers
    'Elsevier BV', 2007
    Co-Authors: Singh Sukhvinder, S.s. Talwar, Rs Srinivasa, S.s. Major
    Abstract:

    ZnO and Zn1−xCdxO nanocrystallites were prepared by oxidation of zinc Arachidate–arachidic acid and zinc Arachidate–cadmium Arachidate–arachidic acid LB multilayers, respectively. The metal content of the multilayers was controlled by manipulation of subphase composition and pH. Precursor multilayers were oxidized in the temperature range of 400 °C–700 °C. The formation of ZnO and Zn1−xCdxO was confirmed by UV–Visible spectroscopy. Uniformly distributed, isolated and nearly mono-dispersed nanocrystallites of ZnO (11 ± 3 nm) and Zn1−xCdxO (18 ± 6 nm) were obtained.© Elsevie

Kelvin G. Lynn - One of the best experts on this subject based on the ideXlab platform.

  • characterization of Arachidate langmuir blodgett films by variable energy positron beams
    Langmuir, 1999
    Co-Authors: T. Marek, Csaba Szeles, Károly Süvegh, Éva Kiss, A. Vértes, Kelvin G. Lynn
    Abstract:

    Arachidate Langmuir−Blodgett (LB) films of different chemical composition and number of monomolecular layers deposited on silylated silica glass substrates were studied by means of positron annihilation spectroscopy. The applied methods included the measurement of the Doppler broadening of the annihilation photopeak with variable energy positron beams and bulk positron lifetime measurements. The studied samples were 58 monomolecular layers (MML) thick Mg- and Cd-Arachidate, arachidic acid (50 MML) and a series of Pb-Arachidate samples with 4, 10, 20, 40, and 58 MML. The investigation showed that the variable energy positron beam technique is capable of measuring the thickness of the deposited LB films. The measured positron annihilation parameters are sensitive to the chemical composition of the films and the behavior of the films in a vacuum. The results confirmed the stability of salt base LB films in high vacuum conditions and showed the desorption of pure acid films. These investigations have also sho...

  • Characterization of Arachidate Langmuir−Blodgett Films by Variable Energy Positron Beams
    Langmuir, 1999
    Co-Authors: T. Marek, Csaba Szeles, Károly Süvegh, Éva Kiss, A. Vértes, Kelvin G. Lynn
    Abstract:

    Arachidate Langmuir−Blodgett (LB) films of different chemical composition and number of monomolecular layers deposited on silylated silica glass substrates were studied by means of positron annihilation spectroscopy. The applied methods included the measurement of the Doppler broadening of the annihilation photopeak with variable energy positron beams and bulk positron lifetime measurements. The studied samples were 58 monomolecular layers (MML) thick Mg- and Cd-Arachidate, arachidic acid (50 MML) and a series of Pb-Arachidate samples with 4, 10, 20, 40, and 58 MML. The investigation showed that the variable energy positron beam technique is capable of measuring the thickness of the deposited LB films. The measured positron annihilation parameters are sensitive to the chemical composition of the films and the behavior of the films in a vacuum. The results confirmed the stability of salt base LB films in high vacuum conditions and showed the desorption of pure acid films. These investigations have also sho...

Ian R. Gentle - One of the best experts on this subject based on the ideXlab platform.

  • Structures of Mixed Langmuir−Blodgett Films of Tetrakis(3,5-di-tert-butylphenyl)porphinatocopper(II) with Cadmium Arachidate: A Grazing Incidence Synchrotron X-ray Diffraction Study
    Langmuir, 2000
    Co-Authors: J. B. Peng, Garry J Foran, Geoffrey T. Barnes, Maxwell J. Crossley, Ian R. Gentle
    Abstract:

    Thin films of metallo-porphyrins have interesting properties which appear to be related to the film structure. Mixed Langmuir−Blodgett (LB) films of tetrakis(3,5-di-tert-butylphenyl)porphinatocopper(II) (TDBPC) with cadmium Arachidate have been studied by grazing incidence X-ray diffraction (GIXD) to investigate their structures and miscibilities. In the two-component films there are two 2-dimensional structures present in the film plane, with geometries and correlation lengths that are independent of the molar ratio of the two compounds. One is from cadmium Arachidate domains, and has a rectangular symmetry (a = 7.44 A, b = 4.95 A, and γ = 90°). The other is from the porphyrin domains and has an oblique symmetry (a = 15.2 A, b = 8.61 A, and γ = 80.3°). The molecular chains of cadmium Arachidate and the macrocycles of the porphyrin are perpendicular to the film plane. The area per porphyrin molecule is 124 A2, consistent with the value obtained from surface pressure−area measurements on the floating monolayers. The components are immiscible. There is no structural correlation between the layers in the LB films, and only those films with a high cadmium Arachidate content exhibit a clear lamellar structure. The presence of long-chain alkane molecules (so-called trigger molecules) in the films did not alter the molecular orientation in the porphyrin domains, but did disturb the domain orientation with respect to the surface normal of both materials.

  • structures of mixed langmuir blodgett films of tetrakis 3 5 di tert butylphenyl porphinatocopper ii with cadmium Arachidate a grazing incidence synchrotron x ray diffraction study
    Langmuir, 2000
    Co-Authors: J. B. Peng, Garry J Foran, Geoffrey T. Barnes, Maxwell J. Crossley, Ian R. Gentle
    Abstract:

    Thin films of metallo-porphyrins have interesting properties which appear to be related to the film structure. Mixed Langmuir−Blodgett (LB) films of tetrakis(3,5-di-tert-butylphenyl)porphinatocopper(II) (TDBPC) with cadmium Arachidate have been studied by grazing incidence X-ray diffraction (GIXD) to investigate their structures and miscibilities. In the two-component films there are two 2-dimensional structures present in the film plane, with geometries and correlation lengths that are independent of the molar ratio of the two compounds. One is from cadmium Arachidate domains, and has a rectangular symmetry (a = 7.44 A, b = 4.95 A, and γ = 90°). The other is from the porphyrin domains and has an oblique symmetry (a = 15.2 A, b = 8.61 A, and γ = 80.3°). The molecular chains of cadmium Arachidate and the macrocycles of the porphyrin are perpendicular to the film plane. The area per porphyrin molecule is 124 A2, consistent with the value obtained from surface pressure−area measurements on the floating monolayers. The components are immiscible. There is no structural correlation between the layers in the LB films, and only those films with a high cadmium Arachidate content exhibit a clear lamellar structure. The presence of long-chain alkane molecules (so-called trigger molecules) in the films did not alter the molecular orientation in the porphyrin domains, but did disturb the domain orientation with respect to the surface normal of both materials.

Raman S. Srinivasa - One of the best experts on this subject based on the ideXlab platform.

  • Enhanced photoluminescence of CdS nanocrystallites in LB multilayers on aqueous treatment
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011
    Co-Authors: Pavan K. Narayanam, Raman S. Srinivasa, S.s. Talwar, S.s. Major
    Abstract:

    Abstract CdS nanocrystallites were formed within the LB matrix of cadmium Arachidate–arachidic acid composite multilayer by post deposition H 2 S exposure of precursor cadmium Arachidate multilayer. The CdS containing multilayers were subjected to post deposition heat treatment in air in the temperature range of 100–300 °C, either directly after the sulphidation process or after being introduced into an aqueous bath. FT-IR spectroscopy was used to study the chemical changes in composite multilayers at different stages of processing. Optical properties of the CdS nanocrystallites were studied by UV–VIS absorption and photoluminescence measurements. A strong enhancement of excitonic emission and suppression of surface states emission from CdS nanocrystallites was observed after heat treatment at 100–150 °C in the case of aqueous treated composite multilayer. X ray reflection and atomic force microscopy show that the aqueous treatment results in expulsion of arachidic acid to the surface of the multilayer resulting in its facile removal during heat treatment. These results suggest that the response to heat treatment of the composite multilayer containing CdS nanocrystallites depends critically on the proximity and access of the unreacted cadmium Arachidate to CdS nanocrystallites. This in turn, provides Cd ions for the passivation of Cd vacancies on the surface of nanocrystallites resulting in a strong enhancement of excitonic emission. Heat treatment at higher temperatures results in drastic reduction of photoluminescence, due to particle growth as well as removal of organic moieties.

  • Effect of cadmium Arachidate on molecular packing of zinc Arachidate LB multilayers
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
    Co-Authors: Pradipta K. Nayak, S.s. Talwar, S.s. Major, Raman S. Srinivasa
    Abstract:

    Abstract Mixed zinc Arachidate–cadmium Arachidate (ZnA–CdA) LB multilayers deposited from varying subphase compositions have been characterized by FTIR and X-ray reflection (XR). The COO − symmetric stretching band of CdA and changes in CH 2 scissoring band were used to monitor the CdA content and nature of molecular packing in the mixed multilayers. The XR pattern of pure ZnA multilayer with bilayer period of ∼47 A corresponds to a rotator phase like ‘loose packing’ in a hexagonal layer cell. However, the presence of low concentrations of cadmium ion in subphase (2–5 mol%) results in biphasic multilayers with bilayer periods of ∼47 and ∼51 A. In the cadmium concentration range of 10–25 mol%, the multilayers exhibit sharp (0 0  l ) peaks in XR pattern, corresponding to a single layered structure with alkyl chains tilted by ∼23° from layer-normal. Increase in the cadmium concentration (30–50 mol%) results in biphasic multilayers with bilayer periods of ∼52 and ∼55 A, the later corresponding to a herringbone type packing of alkyl chains, perpendicular to the layer plane. At higher concentrations of CdA, the layered structure and molecular packing resemble that of pure CdA multilayer.

  • CdxZn1−xS–arachidic acid composite LB films
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
    Co-Authors: Marzieh Parhizkar, Nigvendra Kumar, Pradipta K. Nayak, S.s. Talwar, S.s. Major, Raman S. Srinivasa
    Abstract:

    Abstract Mixed LB multilayers of cadmium Arachidate–zinc Arachidate (CdA–ZnA) have been exposed to H 2 S to form Cd x Zn 1− x S alloy nanoclusters within the multilayers. FTIR and UV–vis spectra of H 2 S exposed multilayers showed that the conversion of Arachidate salt into arachidic acid (AA) and sulphide formation begins in the first 5 min and is completed in ∼3 h of H 2 S exposure. X-ray reflection studies and the nature of CH 2 scissoring band of the composite multilayers show that the formation of sulphide nanoclusters is accompanied by the formation of molecular chain domains with different polymorphic phases of AA, depending upon the relative proportions of CdA and ZnA in the precursor multilayer. Depending upon the CdS and ZnS content, the absorption edge is found to continuously shift from that of pure CdS to that of pure ZnS nanoclusters, indicating the formation of Cd x Zn 1− x S alloy nanoclusters in the arachidic acid matrix. The nanocluster formation is more facile in the mixed archidate multilayers than in pure CdA or ZnA multilayers.

  • cdxzn1 xs arachidic acid composite lb films
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
    Co-Authors: Marzieh Parhizkar, Nigvendra Kumar, Pradipta K. Nayak, S.s. Talwar, S.s. Major, Raman S. Srinivasa
    Abstract:

    Abstract Mixed LB multilayers of cadmium Arachidate–zinc Arachidate (CdA–ZnA) have been exposed to H 2 S to form Cd x Zn 1− x S alloy nanoclusters within the multilayers. FTIR and UV–vis spectra of H 2 S exposed multilayers showed that the conversion of Arachidate salt into arachidic acid (AA) and sulphide formation begins in the first 5 min and is completed in ∼3 h of H 2 S exposure. X-ray reflection studies and the nature of CH 2 scissoring band of the composite multilayers show that the formation of sulphide nanoclusters is accompanied by the formation of molecular chain domains with different polymorphic phases of AA, depending upon the relative proportions of CdA and ZnA in the precursor multilayer. Depending upon the CdS and ZnS content, the absorption edge is found to continuously shift from that of pure CdS to that of pure ZnS nanoclusters, indicating the formation of Cd x Zn 1− x S alloy nanoclusters in the arachidic acid matrix. The nanocluster formation is more facile in the mixed archidate multilayers than in pure CdA or ZnA multilayers.