Nina Daneu | Jožef Stefan Institute (original) (raw)

Papers by Nina Daneu

Research paper thumbnail of A new complex ternary phase in the Al-Cr-Sc push-pull alloy

Journal of Alloys and Compounds, Nov 1, 2018

Research paper thumbnail of Thermoelectric properties of pseudobrookite-based ceramics prepared from natural Fe-Ti-rich heavy mineral sand concentrate

Journal of the European Ceramic Society

Research paper thumbnail of Bismuth Doping in Nanostructured Tetrahedrite: Scalable Synthesis and Thermoelectric Performance

Nanomaterials

In this study, we demonstrate the feasibility of Bi-doped tetrahedrite Cu12Sb4−xBixS13 (x = 0.02–... more In this study, we demonstrate the feasibility of Bi-doped tetrahedrite Cu12Sb4−xBixS13 (x = 0.02–0.20) synthesis in an industrial eccentric vibratory mill using Cu, Sb, Bi and S elemental precursors. High-energy milling was followed by spark plasma sintering. In all the samples, the prevailing content of tetrahedrite Cu12Sb4S13 (71–87%) and famatinite Cu3SbS4 (13–21%), together with small amounts of skinnerite Cu3SbS3, have been detected. The occurrence of the individual Cu-Sb-S phases and oxidation states of bismuth identified as Bi0 and Bi3+ are correlated. The most prominent effect of the simultaneous milling and doping on the thermoelectric properties is a decrease in the total thermal conductivity (κ) with increasing Bi content, in relation with the increasing amount of famatinite and skinnerite contents. The lowest value of κ was achieved for x = 0.2 (1.1 W m−1 K−1 at 675 K). However, this sample also manifests the lowest electrical conductivity σ, combined with relatively unc...

Research paper thumbnail of Polarization in pseudocubic epitaxial relaxed PMN-PT thin films

Applied Physics Letters

Understanding the relationship between structural characteristics and functional properties of co... more Understanding the relationship between structural characteristics and functional properties of complex relaxor ferroelectric thin films is of high interest for designing materials with high performances. In this work, the structure of epitaxial relaxed pulsed-laser-deposited Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT; x = 25, 33, and 40) thin films on LaNiO3/SrTiO3 substrates is analyzed using a variety of diffraction and spectroscopic techniques. While based on the data obtained from high-resolution x-ray diffraction and scanning transmission electron microscopy analysis, the average structure of the PMN-xPT films is metrically cubic, micro-Raman polarimetry measurements indicate the tetragonal-like ferroelectric phase with marked preference for the polarization perpendicular to the film for all three compositions. The results of the Raman scattering analysis are supported by electromechanical properties of the samples, which clearly show that the films have a locally non-centrosymmetric st...

Research paper thumbnail of Twinning in SnO2-based ceramics doped with CoO and Nb2O5: morphology of multiple twins revealed by electron backscatter diffraction

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials

Electron backscatter diffraction (EBSD) was used for the analysis of multiple cyclic twins in cas... more Electron backscatter diffraction (EBSD) was used for the analysis of multiple cyclic twins in cassiterite (SnO2), which form during sintering of SnO2 with small additions of CoO and Nb2O5. Grain misorientation analysis has shown that about one third of all grains contain {101} twin boundaries (TBs). The majority of these grains are contact twins, whereas a small fraction of grains are multiple, mainly cyclic twins. A procedure was developed in MTEX [Bachmann, Hielscher & Schaeben (2010). Solid State Phenom. 160, 63–88] for automated identification of crystallographically different types of cyclic twins and found two main types: coplanar twins composed of three or four domains with a common [010] axis and alternating twins composed of three to seven domains oriented along the [111] axis. Both types of cyclic twins have a characteristic common origin (nucleus) of all TBs, which is positioned eccentric relative to the grain section and the cycle is closed with a shorter non-crystallogr...

Research paper thumbnail of Formation of contact and multiple cyclic cassiterite twins in SnO2-based ceramics co-doped with cobalt and niobium oxides

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials

Contact and multiple cyclic twins of cassiterite commonly form in SnO2-based ceramics when SnO2 i... more Contact and multiple cyclic twins of cassiterite commonly form in SnO2-based ceramics when SnO2 is sintered with small additions of cobalt and niobium oxides (dual doping). In this work, it is shown that the formation of twins is a two-stage process that starts with epitaxial growth of SnO2 on CoNb2O6 and Co4Nb2O9 seeds (twin nucleation stage) and continues with the fast growth of (101) twin contacts (twin growth stage). Both secondary phases form below the temperature of enhanced densification and SnO2 grain growth; CoNb2O6 forms at ∼700°C and Co4Nb2O9 at ∼900°C. They are structurally related to the rutile-type cassiterite and can thus trigger oriented (epitaxial) growth (local recrystallization) of SnO2 domains in different orientations on a single seed particle. While oriented growth of cassiterite on columbite-type CoNb2O6 grains can only result in the formation of contact twins, the Co4Nb2O9 grains with a structure comparable with that of corundum represent suitable sites for t...

Research paper thumbnail of Sustainable Synthesis of Cadmium Sulfide, with Applicability in Photocatalysis, Hydrogen Production, and as an Antibacterial Agent, Using Two Mechanochemical Protocols

Nanomaterials

CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd an... more CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd and S precursors, respectively. The effect of using sodium thiosulfate as an additional sulfur precursor was also investigated (combined milling). The samples were characterized by XRD, Raman spectroscopy, XPS, UV-Vis spectroscopy, PL spectroscopy, DLS, and TEM. Photocatalytic activities of both CdS samples were compared. The photocatalytic activity of CdS, which is produced by combined milling, was superior to that of CdS, and was obtained by an acetate route in the degradation of Orange II under visible light irradiation. Better results for CdS prepared using a combined approach were also evidenced in photocatalytic experiments on hydrogen generation. The antibacterial potential of mechanochemically prepared CdS nanocrystals was also tested on reference strains of E. coli and S. aureus. Susceptibility tests included a 24-h toxicity test, a disk diffusion assay, and respiration monitoring...

Research paper thumbnail of Mechanochemical Synthesis and Characterization of CuInS2/ZnS Nanocrystals

Molecules, 2019

In this study, CuInS2/ZnS nanocrystals were synthesized by a two-step mechanochemical synthesis f... more In this study, CuInS2/ZnS nanocrystals were synthesized by a two-step mechanochemical synthesis for the first time. In the first step, tetragonal CuInS2 was prepared from copper, indium and sulphur precursors. The obtained CuInS2 was further co-milled with zinc acetate dihydrate and sodium sulphide nonahydrate as precursors for cubic ZnS. Structural characterization of the CuInS2/ZnS nanocrystals was performed by X-ray diffraction analysis, Raman spectroscopy and transmission electron microscopy. Specific surface area of the product (86 m2/g) was measured by low-temperature nitrogen adsorption method and zeta potential of the particles dispersed in water was calculated from measurements of their electrophoretic mobility. Optical properties of the nanocrystals were determined using photoluminescence emission spectroscopy.

Research paper thumbnail of SrTiO3/Bi4Ti3O12 Nanoheterostructural Platelets Synthesized by Topotactic Epitaxy as Effective Noble-Metal-Free Photocatalysts for pH-Neutral Hydrogen Evolution

ACS Applied Materials & Interfaces, 2020

Research paper thumbnail of SDS-Stabilized CuInSe2/ZnS Multinanocomposites Prepared by Mechanochemical Synthesis for Advanced Biomedical Application

Nanomaterials, 2020

The CuInSe2/ZnS multiparticulate nanocomposites were first synthesized employing two-step mechano... more The CuInSe2/ZnS multiparticulate nanocomposites were first synthesized employing two-step mechanochemical synthesis. In the first step, tetragonal CuInSe2 crystals prepared from copper, indium and selenium precursors were co-milled with zinc acetate dihydrate and sodium sulfide nonahydrate as precursors for ZnS in different molar ratios by mechanochemical route in a planetary mill. In the second step, the prepared CuInSe2/ZnS nanocrystals were further milled in a circulation mill in sodium dodecyl sulphate (SDS) solution (0.5 wt.%) to stabilize the synthesized nanoparticles. The sodium dodecyl sulphate capped CuInSe2/ZnS 5:0-SDS nanosuspension was shown to be stable for 20 weeks, whereas the CuInSe2/ZnS 4:1-SDS one was stable for about 11 weeks. After sodium dodecyl sulphate capping, unimodal particle size distribution was obtained with particle size medians approaching, respectively, 123 nm and 188 nm for CuInSe2/ZnS 5:0-SDS and CuInSe2/ZnS 4:1-SDS nanocomposites. Successful stabil...

Research paper thumbnail of Growth mode and strain effect on relaxor ferroelectric domains in epitaxial 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3/SrRuO3 heterostructures

RSC Advances, 2021

Strain engineering in epitaxial PMN–33PT films revealed an evolution from a butterfly-shaped diff... more Strain engineering in epitaxial PMN–33PT films revealed an evolution from a butterfly-shaped diffraction for mildly strained films, evidencing the stabilization of relaxor domains, to disc-shaped diffraction patterns for high compressive strains.

Research paper thumbnail of A scalable synthesis route for multiscale defect engineering in the sustainable thermoelectric quaternary sulfide Cu26V2Sn6S32

Research paper thumbnail of Microstructure development in (Co,Ta)-doped SnO2-based ceramics with promising varistor and dielectric properties

Journal of the European Ceramic Society, 2020

Research paper thumbnail of Luminescence properties of Eu3+ activated Y2MoO6 powders calcined at different temperatures

Processing and Application of Ceramics, 2020

In the last decade, an immense progress has been made in white LEDs, mainly due to the developmen... more In the last decade, an immense progress has been made in white LEDs, mainly due to the development of red-emitting phosphors. In this paper, we report on the synthesis of Eu3+ activated Y2MoO6 by a self-initiated and self-sustained method. The obtained powder was calcined at various temperatures in the 600-1400?C range and examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence spectroscopy (PL). The results revealed that all powders are single phase Y2MoO6:Eu3+, with particle size in the nanorange at lower treatment temperatures (600 and 800?C) and in the microrange at higher calcination temperatures (1000-1400?C). The obtained powders are promising materials for white light-emitting diodes as they can efficiently absorb energy in 324-425 nm region (near-UV to blue light region) and emit at 611 nm in the red region of the spectrum, while exhibiting high thermal and chemical stability.

Research paper thumbnail of Tetrahedrites synthesized via scalable mechanochemical process and spark plasma sintering

Journal of the European Ceramic Society, 2020

Research paper thumbnail of Charge compensation and electrical characteristics of Ta2O5–doped SnO2–CoO ceramics

Journal of the European Ceramic Society, 2019

Research paper thumbnail of An in vitro evaluation of the variation in surface characteristics of bioactive glass coated SS316L for load bearing application

Surface and Coatings Technology, 2019

Research paper thumbnail of Twinning and charge compensation in Nb2O5–doped SnO2–CoO ceramics exhibiting promising varistor characteristics

Ceramics International, 2018

Research paper thumbnail of Phase formation, microstructure development and thermoelectric properties of (ZnO)kIn2O3 ceramics

Journal of the European Ceramic Society, 2017

Research paper thumbnail of On the origin of 'iron-cross' twins of pyrite from Mt. Katarina, Slovenia

Mineralogical Magazine, 2016

Iron-cross twins of pyrite are well known among mineralogists, however it is quite surprising tha... more Iron-cross twins of pyrite are well known among mineralogists, however it is quite surprising that the conditions of their formation remain unexplored. To address this question we studied pyrite twins from the Upper Permian silts of Mt. Katarina near Ljubljana (Slovenia), which represent one of the most typical geological environments for twinned pyrite. Mineralization of pyrite starts with a reduction of the primary red-coloured hematite-rich sediment by sulfide-rich fluids that penetrated the strata. A short period of magnetite crystallization is observed prior to pyrite crystallization, which indicates a gradual reduction process. Sulfur isotope analysis of pyrite shows an enrichment in δ34S, suggesting its origin from the neighbouring red-bed deposit. Other sulfides, such as chalcopyrite and galena, formed at the end of pyrite crystallization. Remnants of mineralizing fluids trapped at the interfaces between the inclusions and host pyrite show trace amounts of Pb and Cu, indicat...

Research paper thumbnail of A new complex ternary phase in the Al-Cr-Sc push-pull alloy

Journal of Alloys and Compounds, Nov 1, 2018

Research paper thumbnail of Thermoelectric properties of pseudobrookite-based ceramics prepared from natural Fe-Ti-rich heavy mineral sand concentrate

Journal of the European Ceramic Society

Research paper thumbnail of Bismuth Doping in Nanostructured Tetrahedrite: Scalable Synthesis and Thermoelectric Performance

Nanomaterials

In this study, we demonstrate the feasibility of Bi-doped tetrahedrite Cu12Sb4−xBixS13 (x = 0.02–... more In this study, we demonstrate the feasibility of Bi-doped tetrahedrite Cu12Sb4−xBixS13 (x = 0.02–0.20) synthesis in an industrial eccentric vibratory mill using Cu, Sb, Bi and S elemental precursors. High-energy milling was followed by spark plasma sintering. In all the samples, the prevailing content of tetrahedrite Cu12Sb4S13 (71–87%) and famatinite Cu3SbS4 (13–21%), together with small amounts of skinnerite Cu3SbS3, have been detected. The occurrence of the individual Cu-Sb-S phases and oxidation states of bismuth identified as Bi0 and Bi3+ are correlated. The most prominent effect of the simultaneous milling and doping on the thermoelectric properties is a decrease in the total thermal conductivity (κ) with increasing Bi content, in relation with the increasing amount of famatinite and skinnerite contents. The lowest value of κ was achieved for x = 0.2 (1.1 W m−1 K−1 at 675 K). However, this sample also manifests the lowest electrical conductivity σ, combined with relatively unc...

Research paper thumbnail of Polarization in pseudocubic epitaxial relaxed PMN-PT thin films

Applied Physics Letters

Understanding the relationship between structural characteristics and functional properties of co... more Understanding the relationship between structural characteristics and functional properties of complex relaxor ferroelectric thin films is of high interest for designing materials with high performances. In this work, the structure of epitaxial relaxed pulsed-laser-deposited Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT; x = 25, 33, and 40) thin films on LaNiO3/SrTiO3 substrates is analyzed using a variety of diffraction and spectroscopic techniques. While based on the data obtained from high-resolution x-ray diffraction and scanning transmission electron microscopy analysis, the average structure of the PMN-xPT films is metrically cubic, micro-Raman polarimetry measurements indicate the tetragonal-like ferroelectric phase with marked preference for the polarization perpendicular to the film for all three compositions. The results of the Raman scattering analysis are supported by electromechanical properties of the samples, which clearly show that the films have a locally non-centrosymmetric st...

Research paper thumbnail of Twinning in SnO2-based ceramics doped with CoO and Nb2O5: morphology of multiple twins revealed by electron backscatter diffraction

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials

Electron backscatter diffraction (EBSD) was used for the analysis of multiple cyclic twins in cas... more Electron backscatter diffraction (EBSD) was used for the analysis of multiple cyclic twins in cassiterite (SnO2), which form during sintering of SnO2 with small additions of CoO and Nb2O5. Grain misorientation analysis has shown that about one third of all grains contain {101} twin boundaries (TBs). The majority of these grains are contact twins, whereas a small fraction of grains are multiple, mainly cyclic twins. A procedure was developed in MTEX [Bachmann, Hielscher & Schaeben (2010). Solid State Phenom. 160, 63–88] for automated identification of crystallographically different types of cyclic twins and found two main types: coplanar twins composed of three or four domains with a common [010] axis and alternating twins composed of three to seven domains oriented along the [111] axis. Both types of cyclic twins have a characteristic common origin (nucleus) of all TBs, which is positioned eccentric relative to the grain section and the cycle is closed with a shorter non-crystallogr...

Research paper thumbnail of Formation of contact and multiple cyclic cassiterite twins in SnO2-based ceramics co-doped with cobalt and niobium oxides

Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials

Contact and multiple cyclic twins of cassiterite commonly form in SnO2-based ceramics when SnO2 i... more Contact and multiple cyclic twins of cassiterite commonly form in SnO2-based ceramics when SnO2 is sintered with small additions of cobalt and niobium oxides (dual doping). In this work, it is shown that the formation of twins is a two-stage process that starts with epitaxial growth of SnO2 on CoNb2O6 and Co4Nb2O9 seeds (twin nucleation stage) and continues with the fast growth of (101) twin contacts (twin growth stage). Both secondary phases form below the temperature of enhanced densification and SnO2 grain growth; CoNb2O6 forms at ∼700°C and Co4Nb2O9 at ∼900°C. They are structurally related to the rutile-type cassiterite and can thus trigger oriented (epitaxial) growth (local recrystallization) of SnO2 domains in different orientations on a single seed particle. While oriented growth of cassiterite on columbite-type CoNb2O6 grains can only result in the formation of contact twins, the Co4Nb2O9 grains with a structure comparable with that of corundum represent suitable sites for t...

Research paper thumbnail of Sustainable Synthesis of Cadmium Sulfide, with Applicability in Photocatalysis, Hydrogen Production, and as an Antibacterial Agent, Using Two Mechanochemical Protocols

Nanomaterials

CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd an... more CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd and S precursors, respectively. The effect of using sodium thiosulfate as an additional sulfur precursor was also investigated (combined milling). The samples were characterized by XRD, Raman spectroscopy, XPS, UV-Vis spectroscopy, PL spectroscopy, DLS, and TEM. Photocatalytic activities of both CdS samples were compared. The photocatalytic activity of CdS, which is produced by combined milling, was superior to that of CdS, and was obtained by an acetate route in the degradation of Orange II under visible light irradiation. Better results for CdS prepared using a combined approach were also evidenced in photocatalytic experiments on hydrogen generation. The antibacterial potential of mechanochemically prepared CdS nanocrystals was also tested on reference strains of E. coli and S. aureus. Susceptibility tests included a 24-h toxicity test, a disk diffusion assay, and respiration monitoring...

Research paper thumbnail of Mechanochemical Synthesis and Characterization of CuInS2/ZnS Nanocrystals

Molecules, 2019

In this study, CuInS2/ZnS nanocrystals were synthesized by a two-step mechanochemical synthesis f... more In this study, CuInS2/ZnS nanocrystals were synthesized by a two-step mechanochemical synthesis for the first time. In the first step, tetragonal CuInS2 was prepared from copper, indium and sulphur precursors. The obtained CuInS2 was further co-milled with zinc acetate dihydrate and sodium sulphide nonahydrate as precursors for cubic ZnS. Structural characterization of the CuInS2/ZnS nanocrystals was performed by X-ray diffraction analysis, Raman spectroscopy and transmission electron microscopy. Specific surface area of the product (86 m2/g) was measured by low-temperature nitrogen adsorption method and zeta potential of the particles dispersed in water was calculated from measurements of their electrophoretic mobility. Optical properties of the nanocrystals were determined using photoluminescence emission spectroscopy.

Research paper thumbnail of SrTiO3/Bi4Ti3O12 Nanoheterostructural Platelets Synthesized by Topotactic Epitaxy as Effective Noble-Metal-Free Photocatalysts for pH-Neutral Hydrogen Evolution

ACS Applied Materials & Interfaces, 2020

Research paper thumbnail of SDS-Stabilized CuInSe2/ZnS Multinanocomposites Prepared by Mechanochemical Synthesis for Advanced Biomedical Application

Nanomaterials, 2020

The CuInSe2/ZnS multiparticulate nanocomposites were first synthesized employing two-step mechano... more The CuInSe2/ZnS multiparticulate nanocomposites were first synthesized employing two-step mechanochemical synthesis. In the first step, tetragonal CuInSe2 crystals prepared from copper, indium and selenium precursors were co-milled with zinc acetate dihydrate and sodium sulfide nonahydrate as precursors for ZnS in different molar ratios by mechanochemical route in a planetary mill. In the second step, the prepared CuInSe2/ZnS nanocrystals were further milled in a circulation mill in sodium dodecyl sulphate (SDS) solution (0.5 wt.%) to stabilize the synthesized nanoparticles. The sodium dodecyl sulphate capped CuInSe2/ZnS 5:0-SDS nanosuspension was shown to be stable for 20 weeks, whereas the CuInSe2/ZnS 4:1-SDS one was stable for about 11 weeks. After sodium dodecyl sulphate capping, unimodal particle size distribution was obtained with particle size medians approaching, respectively, 123 nm and 188 nm for CuInSe2/ZnS 5:0-SDS and CuInSe2/ZnS 4:1-SDS nanocomposites. Successful stabil...

Research paper thumbnail of Growth mode and strain effect on relaxor ferroelectric domains in epitaxial 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3/SrRuO3 heterostructures

RSC Advances, 2021

Strain engineering in epitaxial PMN–33PT films revealed an evolution from a butterfly-shaped diff... more Strain engineering in epitaxial PMN–33PT films revealed an evolution from a butterfly-shaped diffraction for mildly strained films, evidencing the stabilization of relaxor domains, to disc-shaped diffraction patterns for high compressive strains.

Research paper thumbnail of A scalable synthesis route for multiscale defect engineering in the sustainable thermoelectric quaternary sulfide Cu26V2Sn6S32

Research paper thumbnail of Microstructure development in (Co,Ta)-doped SnO2-based ceramics with promising varistor and dielectric properties

Journal of the European Ceramic Society, 2020

Research paper thumbnail of Luminescence properties of Eu3+ activated Y2MoO6 powders calcined at different temperatures

Processing and Application of Ceramics, 2020

In the last decade, an immense progress has been made in white LEDs, mainly due to the developmen... more In the last decade, an immense progress has been made in white LEDs, mainly due to the development of red-emitting phosphors. In this paper, we report on the synthesis of Eu3+ activated Y2MoO6 by a self-initiated and self-sustained method. The obtained powder was calcined at various temperatures in the 600-1400?C range and examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence spectroscopy (PL). The results revealed that all powders are single phase Y2MoO6:Eu3+, with particle size in the nanorange at lower treatment temperatures (600 and 800?C) and in the microrange at higher calcination temperatures (1000-1400?C). The obtained powders are promising materials for white light-emitting diodes as they can efficiently absorb energy in 324-425 nm region (near-UV to blue light region) and emit at 611 nm in the red region of the spectrum, while exhibiting high thermal and chemical stability.

Research paper thumbnail of Tetrahedrites synthesized via scalable mechanochemical process and spark plasma sintering

Journal of the European Ceramic Society, 2020

Research paper thumbnail of Charge compensation and electrical characteristics of Ta2O5–doped SnO2–CoO ceramics

Journal of the European Ceramic Society, 2019

Research paper thumbnail of An in vitro evaluation of the variation in surface characteristics of bioactive glass coated SS316L for load bearing application

Surface and Coatings Technology, 2019

Research paper thumbnail of Twinning and charge compensation in Nb2O5–doped SnO2–CoO ceramics exhibiting promising varistor characteristics

Ceramics International, 2018

Research paper thumbnail of Phase formation, microstructure development and thermoelectric properties of (ZnO)kIn2O3 ceramics

Journal of the European Ceramic Society, 2017

Research paper thumbnail of On the origin of 'iron-cross' twins of pyrite from Mt. Katarina, Slovenia

Mineralogical Magazine, 2016

Iron-cross twins of pyrite are well known among mineralogists, however it is quite surprising tha... more Iron-cross twins of pyrite are well known among mineralogists, however it is quite surprising that the conditions of their formation remain unexplored. To address this question we studied pyrite twins from the Upper Permian silts of Mt. Katarina near Ljubljana (Slovenia), which represent one of the most typical geological environments for twinned pyrite. Mineralization of pyrite starts with a reduction of the primary red-coloured hematite-rich sediment by sulfide-rich fluids that penetrated the strata. A short period of magnetite crystallization is observed prior to pyrite crystallization, which indicates a gradual reduction process. Sulfur isotope analysis of pyrite shows an enrichment in δ34S, suggesting its origin from the neighbouring red-bed deposit. Other sulfides, such as chalcopyrite and galena, formed at the end of pyrite crystallization. Remnants of mineralizing fluids trapped at the interfaces between the inclusions and host pyrite show trace amounts of Pb and Cu, indicat...