Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Molecular Engineering of Exchange Bias in Fe3GeTe2/Molecule Heterostructures(Amer Chemical Soc, 2025) Sharma, Mayank; Jo, Junhyeon; Avedissian, Garen; Bayindir, Bertug; Kang, Jun; Sahin, Hasan; Hueso, Luis E.Molecules offer a versatile route to tailor magnetism through chemical design and spin-state control. When integrated with surface-sensitive layered magnets, molecules can not only exhibit tunable magnetic properties or even activate distinct magnetic phases but can also interact with the layered magnets to manipulate their magnetic dynamics. Here, we demonstrate tunable exchange bias in hybrid heterostructures composed of the layered ferromagnet Fe3GeTe2 (FGT) and metallophthalocyanine (MPc) molecules having different central transition ions: MnPc, ZnPc, and H2Pc. The MnPc/FGT system exhibits a robust exchange bias of 1000 Oe at 10 K, with a record-high exchange bias-to-coercivity ratio of 0.37, attributed to the antiferromagnetic nature of MnPc. Surprisingly, the diamagnetic ZnPc induces a finite exchange bias of 200 Oe, highlighting the contribution of the emerging spinterface effect. In contrast, the metal-free H2Pc yields no exchange bias, underscoring the essential role of designed molecules for magnetic interaction. First-principles calculations reveal energetically favorable stacking configurations and spin alignments, in agreement with experimental observations. These results highlight the potential of molecular functionalization on magnetism, enabling the on-demand engineering of layered magnetic systems.Article Benzoxazine-Linked Porous Organic Networks for Effective Iodine Capture(Royal Soc Chemistry, 2025) Canturk, Batu Sercan; Erdogmus, Mustafa; Gecalp, Yasmin; Sahin, Hasan; Buyukcakir, OnurThis study presents, for the first time, the investigation of a benzoxazine-linked porous organic network (BPON) for iodine capture. BPON was synthesized through the Mannich condensation of paraformaldehyde, melamine, and phloroglucinol. The porous structure and heteroatom-rich skeleton of BPON make it a promising adsorbent platform for iodine capture. BPON demonstrated an effective iodine capture capability in the vapour phase (3.32 g g-1) and an impressive uptake capacity in the aqueous phase (2.80 g g-1 capacity, 90.4% removal efficiency in 12 hours). To investigate the effect of curing on iodine capture, BPON was thermally cured to prepare thermally cured benzoxazine-linked porous organic networks (cBPONs) at three different temperatures: 200, 250, and 300 degrees C. cBPONs demonstrated an iodine capture capacity of up to 2.20 g g-1 and 1.67 g g-1 for vapour and aqueous phases, respectively. The iodine capture mechanism of BPON was investigated using various ex situ analyses, including Fourier transform infrared (FT-IR), Raman spectra, and X-ray photoelectron spectra (XPS). Structural analysis and theoretical calculations indicated the formation of a charge-transfer complex upon iodine capture, leading to the generation of polyiodide species. This study demonstrates the potential of BPONs for iodine capture and paves the way for developing new polymeric adsorbents for capturing iodine from air and water.Article Citation - WoS: 1Citation - Scopus: 2Scalable Growth of Optically Uniform Mows2 Alloys by Sulfurization of Ultrathin Mo/W Stacks(Elsevier Sci Ltd, 2025) Panasci, Salvatore Ethan; Schiliro, Emanuela; Koos, Antal; Kutlu, Tayfun; Sahin, Hasan; Roccaforte, Fabrizio; Giannazzo, FilippoTwo-dimensional (2D) transition metal dichalcogenides (TMDs) ternary alloys, such as MoxW1-xS2, are very appealing for the possibility of continuously tuning their excitonic bandgap by the composition. However, the deposition of ultra-thin (monolayers or few-layers) alloys with laterally uniform composition on large area represents a main challenge of currently adopted synthesis methods. In this work, we demonstrated the growth of highly uniform Mo0.5W0.5S2 bi-layers on cm2 size SiO2/Si substrates by employing a simple and scalable approach, i.e. the sulfurization of a pre-deposited ultra-thin Mo/W stack at a temperature of 700 degrees C. Comparison of Mo(1.2 nm)/SiO2, W(1.2 nm)/SiO2, and Mo(1.2 nm)/W(1.2 nm)/SiO2 samples after identical sulfurization conditions revealed very different results, i.e. (i) a uniform monolayer (1L) MoS2 film, (ii) separated multilayer WS2 islands, and (iii) a uniform bilayer (2L) Mo0.5W0.5S2 film. This indicates how W surface diffusion and coalescence on SiO2 surface plays a main role in WS2 islands formation, whereas the reaction between S vapour with Mo films or Mo/W stacks represents the dominant mechanism for the formation of MoS2 and the MoWS2 alloy. Micro-photoluminescence (PL) mapping of the obtained 2L-Mo0.5W0.5S2 film showed an excellent uniformity of light emission on large area with an exciton peak at 1.97 eV, significantly blue-shifted with respect to PL emission of 1L-MoS2 at 1.86 eV. Such highly uniform optical properties make the grown MoWS2 alloy very promising for optoelectronic applications.Article Novel Single Layers of Holey Crystalline Strcutures of Hf8s12 With Diverse Magnetic States(Elsevier, 2025) Kutlu, Tayfun; Ercem, Onur; Yagmurcukardes, Mehmet; Sahin, HasanMotivated by recent experiments revealing the synthesizability of novel M 8 X 12 (where M=transition metal and X=S, Se, or Te) type holey structure transition metal chalcogenide crystals such as W8Se12, the structural, electronic and vibrational properties of the single layer Hf8S12 are investigated. Density functional theory (DFT) based total energy optimizations and dynamic stability analysis show that hafnium disulfide crystals with the known 1T phase are stabilized in the holey crystal structure represented by the chemical formula Hf8S12. While 1T-HfS2 crystals are nonmagnetic, holey Hf8S12 material exhibits 4 different magnetic states along with the ferromagnetic ground state. All these magnetic states display indirect or quasi-indirect narrow bandgap semiconducting behavior. Moreover, it is shown that the in-plane stiffness and Poisson ratio values of each possible magnetic phase of Hf8S12 has a distinctive angle dependency against applied strain. Its stable crystal structure and the magnetic diversity show that Hf8S12 can bean important candidate for magneto-mechanical applications.Article Citation - WoS: 2Citation - Scopus: 3Development of Mg-Alginate Based Self Disassociative Bio-Ink for Magnetic Bio-Patterning of 3d Tumor Models(Wiley-v C H verlag Gmbh, 2024) Coban, Basak; Baskurt, Mehmet; Sahin, Hasan; Arslan-Yildiz, AhuAlginate forms a hydrogel via physical cross-linking with divalent cations. In literature, Ca2+ is mostly utilized due to strong interactions but additional procedures are required to disassociate Ca-alginate hydrogels. On the other hand, Mg-alginate hydrogels disassociate spontaneously, which might benefit certain applications. This study introduces Mg-alginate as the main component of a bio-ink for the first time to obtain 3D tumor models by magnetic bio-patterning technique. The bio-ink contains magnetic nanoparticles (MNPs) for magnetic manipulation, Mg-alginate hydrogel as a sacrificial material, and cells. The applicability of the methodology is tested for the formation of 3D tumor models using HeLa, SaOS-2, and SH-SY5Y cells. Long-term cultures are examined by Live/dead and MTT analysis and revealed high cell viability. Subsequently, Collagen and F-actin expressions are observed successfully in 3D tumor models. Finally, the anti-cancer drug Doxorubicin (DOX) effect is investigated on 3D tumor models, and IC50 values is calculated to assess the drug response. As a result, significantly higher drug resistance is observed for bio-patterned 3D tumor models up to tenfold compared to 2D control. Overall, Mg-alginate hydrogel is successfully used to form bio-patterned 3D tumor models, and the applicability of the model is shown effectively, especially as a drug screening platform.Article Citation - WoS: 1Citation - Scopus: 1Experimental and Theoretical Investigation of Synthesis and Properties of Dodecanethiol-Functionalized Mos<sub>2</Sub>(Royal Soc Chemistry, 2023) Duran, Tuna A.; Şahin, Hasan; Sabani, Denis; Milosevic, Milorad V.; Sahin, HasanHerein, we investigate the DDT (1-dodecanethiol) functionalization of exfoliated MoS2 by using experimental and theoretical tools. For the functionalization of MoS2, DDT treatment was incorporated into the conventional NMP (N-methyl pyrrolidone) exfoliation procedure. Afterward, it has been demonstrated that the functionalization process is successful through optical, morphological and theoretical analysis. The D, G and 2LA peaks seen in the Raman spectrum of exfoliated NMP-MoS2 particles, indicate the formation of graphitic species on MoS2 sheets. In addition, as the DDT ratio increases, the vacant sites on MoS2 sheets diminish. Moreover, at an optimized ratio of DDT-NMP, the maximum number of graphitic quantum dots (GQDs) is observed on MoS2 nanosheets. Specifically, the STEM and AFM data confirm that GQDs reside on the MoS2 nano-sheets and also that the particle size of the DDT-MoS2 is mostly fixed, while the NMP-MoS2 show many smaller and distributed sizes. The comparison of PL intensities of the NMP-MoS2 and DDT-MoS2 samples states a 10-fold increment is visible, and a 60-fold increment in NIR region photoluminescent properties. Moreover, our results lay out understanding and perceptions on the surface and edge chemistry of exfoliated MoS2 and open up more opportunities for MoS2 and GQD particles with broader applications.