Journal of Materials Chemistry C最新文献

{"title":"Intricate carrier dynamics of bismuth halide perovskites: localized excitons and polarons†","authors":"Naveen Kumar Tailor, Sanchi Monga, Saurabh K. Saini, Mahesh Kumar, Saswata Bhattacharya and Soumitra Satapathi","doi":"10.1039/D5TC00498E","DOIUrl":"https://doi.org/10.1039/D5TC00498E","url":null,"abstract":"<p >The interaction between carriers and photons in halide perovskites gives rise to intriguing phenomena in their excited states. In particular, bismuth halide perovskites exhibit behavior that extends beyond free carriers, involving excitons and polarons. Here, we report the steady state and excited state dynamics in the lead-free A<small>₃</small>Bi<small>₂</small>I<small>₉</small> [A = FA (formamidinium), MA (methylammonium), Cs (cesium)] perovskite derivatives. The A<small>₃</small>Bi<small>₂</small>I<small>₉</small> system exhibits strong excitonic peaks in the absorption spectra because of defect-related direct-bound excitons. The emission from self-trapped excitons influenced by carrier-phonon coupling and exciton–exciton interactions results in broad photoluminescence spectra. The low-energy photo-induced absorption (PIA-L) band below the bandgap energy is attributed to band gap renormalization (BGR) and the formation of self-trapped excitons (STSs) through electron-acoustic phonon coupling. Hot carrier cooling results in a transient absorption response and the occupation of modified band edge states. The interplay between BGR and polaron formation plays a crucial role in determining the amplitude of PIA-L during the cooling process. We observe that the carrier dynamics in the A<small>₃</small>Bi<small>₂</small>I<small>₉</small> system are mostly dominated by localized excitons and small polarons. This study enhances our understanding of the fundamental processes governing their optoelectronic behavior and paves the way for their further utilization in advanced device applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10119-10129"},"PeriodicalIF":5.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Super-wide-range tunable emission across NIR-II and NIR-III achieved by B-site cation co-substitution in Ni2+-doped double perovskites for NIR light sources†","authors":"Yifu Zhuo, Yaping Niu, Fugen Wu, Jie Li, Yun Wang, Qi Zhang, Yun Teng, Xiaozhu Xie, Huafeng Dong and Zhongfei Mu","doi":"10.1039/D5TC00613A","DOIUrl":"https://doi.org/10.1039/D5TC00613A","url":null,"abstract":"<p >Long-wavelength (1000–2500 nm) near-infrared (LWNIR) phosphors present important application prospects in biomedical and nondestructive testing. A major challenge for current researchers is obtaining phosphors with super-wide-range emission across the NIR-II and NIR-III spectral regions, which is highly advantageous for the development of NIR light sources. Ni<small>²⁺</small> is a prominent activator for LWNIR emission and is sensitive to the octahedral crystal field environment. Herein, a series of Ni<small>²⁺</small>-doped Sr<small>₂</small>B′B′′O<small>₆</small> (B′<small>³⁺</small> = Ga, Sc; B′′<small>⁵⁺</small> = Ta, Sb) phosphors with double perovskite structures was investigated. Through crystal field engineering of B-site cations, specifically Sc<small>³⁺</small>–Sb<small>⁵⁺</small> co-substitution for Ga<small>³⁺</small>–Ta<small>⁵⁺</small>, the emission peak of Ni<small>²⁺</small> was tuned from 1295 to 1665 nm. Such a super-wide-range tunable emission of up to 370 nm was unprecedented. The emission spectra of Sr<small>₂</small>Ga<small>_{1−<em>x</em>}</small>Sc<small>_<em>x</em></small>Ta<small>_{1−<em>y</em>}</small>Sb<small>_<em>y</em></small>O<small>₆</small>:0.01Ni<small>²⁺</small> solid solution phosphors ranged from 1000 to 2100 nm (across NIR-II and NIR-III). The excitation peak was correspondingly shifted from 398 to 454 nm, which was suitable for commercial near-ultraviolet and blue LEDs. The potential applications of our phosphors in biomedical imaging and nondestructive testing were demonstrated. This work not only developed an efficient super-wide-range tunable emission phosphor suitable for LWNIR light sources but also revealed the emission characteristics of Ni<small>²⁺</small>-doped double perovskites, providing important technical guidance for achieving LWNIR emission and developing large-range tunable phosphors.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10621-10631"},"PeriodicalIF":5.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuning the magnetic state and topological transition of monolayer Kagome Co3Pb3SSe with large magnetic anisotropy†","authors":"Yating Li, Wenzhe Zhou, Chuyu Li, Xianjuan He and Fangping Ouyang","doi":"10.1039/D5TC00898K","DOIUrl":"https://doi.org/10.1039/D5TC00898K","url":null,"abstract":"<p >Ferromagnetic topological insulators (TIs) have recently garnered tremendous attention as a platform for investigating novel physical phenomena and innovative design of low-power-consumption spintronic devices. Co<small>₃</small>X<small>₃</small>Y<small>₂</small> monolayers are a promising topological system with a large quantum anomalous Hall effect (QAHE), but they suffer from low magnetic anisotropy. To address this limitation, we construct a Janus Kagome Co<small>₃</small>Pb<small>₃</small>SSe monolayer by introducing heavy elements to enhance spin–orbit coupling (SOC) and break mirror symmetry. Janus Co<small>₃</small>Pb<small>₃</small>SSe is a Weyl semimetal with a high Chern number (|<em>C</em>| = 3) and a substantial magnetic anisotropy of 2.613 meV per unit. It also exhibits a large band gap of 79.8 meV, which is robust against external strain, and a Curie temperature (<em>T</em><small>_C</small>) of 167 K. Notably, strain can induce multistate transitions in the material. Under a strain of −1%, attributed to the combined effects of super-exchange and direct exchange, there is a magnetic ground state transition from ferromagnetic (FM) to antiferromagnetic (AFM). At a strain of −2%, a phase transition from a topological insulator (TI) to a metallic state is observed. Under a 5% tensile strain, <em>T</em><small>_C</small> significantly increases to 348 K, thus enabling the material to be applied at room temperature. Our findings enrich researches on ferromagnetic TIs of Janus Kagome systems.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10924-10930"},"PeriodicalIF":5.7,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polymorphism-induced multi-functional crystal photonics achieved by a highly luminescent benzofuranyl molecule having a tetrafluorophenylene core†","authors":"Takumi Matsuo and Shotaro Hayashi","doi":"10.1039/D5TC00817D","DOIUrl":"https://doi.org/10.1039/D5TC00817D","url":null,"abstract":"<p >Luminescent organic single crystals are attractive as components of miniaturized photonic integrated circuits such as optical waveguides, lasers, and optical resonators. Various functions have been discovered by designing chemical or crystal structures. The optical characteristics can be modulated by designing the crystal structures. Various polymorphic compounds have been reported, and differences in luminescence colors have been well-explained by the differences in the crystal structures. However, drastic modulation of the photonics functions has not been reported. We report here multi-functional photonics achieved by a highly luminescent and polymorphic compound, 1,4-bis(benzofuran-2-yl)-2,3,5,6-tetrafluorophenylene, named <strong>BFTFP</strong>. <strong>BFTFP</strong> exhibited three types of crystal structures: <strong>BFTFP_α</strong>: a flexible fiber, <strong>BFTFP_β</strong>: a rigid block, and <strong>BFTFP_γ</strong>: a plate. Depending on each crystal's morphology or emission properties, specific photonic functions assigned for each crystal, <strong>BFTFP_α</strong>, <strong>BFTFP_β</strong>, and <strong>BFTFP_γ</strong>, respectively, were developed. <strong>BFTFP_α</strong> exhibited elastic flexibility with optical waveguiding. Although elastic organic single crystals tend to be less luminescent, the <strong>BFTFP_α</strong> crystal possessed 52% of <em>Φ</em><small>_PL</small> which was one of the highest among previously reported elastic organic single crystals. <strong>BFTFP_β</strong> exhibited amplified spontaneous emission under excitation using a nanosecond pulsed laser due to their rigidity and monomeric luminescence. Platelet crystals of <strong>BFTFP_γ</strong> exhibited intense luminescence from their basal facets, making them ideal media for highly luminant photonic devices such as vertical cavity surface emitting lasers.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10944-10953"},"PeriodicalIF":5.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zinc oxide-decorated MIL-53(Al)-derived porous carbon for supercapacitor devices†","authors":"Arpad Mihai Rostas, Ahmet Gungor, Angela M. Kasza, Feray Bakan Misirlioglu, Alexandru Turza, Lucian Barbu-Tudoran, Emre Erdem and Maria Mihet","doi":"10.1039/D5TC00966A","DOIUrl":"https://doi.org/10.1039/D5TC00966A","url":null,"abstract":"<p >In this study, we present a facile and direct approach for the synthesis of ordered mesoporous metal–organic framework (MOF)-derived carbon materials, uniformly adorned with zinc oxide (ZnO), to serve as electrode materials for supercapacitor applications. The method involves the impregnation of zinc nitrate into both the as-synthesized (as) and activated low-temperature (lt) forms of the MIL-53(Al) metal–organic framework, which are subsequently employed as precursors to fabricate ZnO-decorated carbon structures (ZnO@C) through simultaneous decomposition under thermal treatment in an Ar atmosphere. The resultant ZnO@C(as) and ZnO@C(lt) materials exhibit a channel-like carbon morphology with uniformly distributed ZnO and residual alumina nanoparticles and a bimodal porous structure with pores approximately 8.5 and 15 nm in size. Additionally, a greater concentration of carbon-related defect centers was identified in ZnO@C(as) relative to ZnO@C(lt), as evidenced by Raman, and electron paramagnetic resonance spectroscopy. When utilized as electrode materials in both symmetric and asymmetric supercapacitor devices, the ZnO@C materials demonstrated exceptional performance, achieving energy and power densities of up to 30.5 W h kg<small>⁻¹</small> and 388 kW kg<small>⁻¹</small>, respectively, and exhibiting coulombic efficiencies exceeding 95% in all instances.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10342-10355"},"PeriodicalIF":5.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/tc/d5tc00966a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of nonlinear optical properties in GaN nanoparticles and nanosheets spanning deep ultraviolet to near-infrared wavelengths","authors":"Zhixin Wu, Guowei Liu, Xuezhi Zhao, Hongkai Ren, Boyao Li, Junjie Huang and Jinghua Sun","doi":"10.1039/D5TC00218D","DOIUrl":"https://doi.org/10.1039/D5TC00218D","url":null,"abstract":"<p >The nonlinear optical behavior of the wide bandgap semiconductor gallium nitride (GaN), manifested in both its crystalline and film forms, has garnered significant attention. Considering the modified properties when GaN is reduced to the nanometer scale, a comprehensive investigation of the nonlinear optical properties of GaN nanomaterials across the spectral range from deep ultraviolet to near-infrared is conducted using ultrafast picosecond pulse lasers. When subjected to lower peak power lasers, these nanomaterials displayed a broadband saturable absorption effect resulting from single-photon absorption. In contrast, exposure to higher peak power lasers led to a reverse saturable absorption effect, driven by two-photon or three-photon absorption, covering wavelengths from deep ultraviolet to infrared. Utilizing the semiconductor band structure model, the electron transition mechanisms from the valence band or defect states to the conduction band were analyzed. At the wavelengths of 266 nm, 355 nm, 532 nm, and 1064 nm, the modulation depths of the saturable absorption effect observed in GaN nanosheets were calculated as 57.03%, 109.15%, 376.23%, and 76.03%, respectively. Concurrently, the minimum normalized transmittances associated with the optical limiting effect at these wavelengths were recorded at 17.46%, 25.27%, 30.06%, and 41.68%. Comparative analysis reveals that nonlinear effects are more pronounced in GaN nanomaterials than in bulk materials, attributed to their nanoscale dimensions and an increase in defect density. Experimental findings demonstrate that GaN nanosheets and nanoparticles hold substantial promise as broadband nonlinear optoelectronic devices, particularly serving as rare saturable absorbers and optical limiters for ultraviolet and deep ultraviolet lasers. This study provides a direction for research on wide bandgap semiconductor nanomaterials as nonlinear absorption materials and underscores their significant application value.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10931-10943"},"PeriodicalIF":5.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Balancing the molecular twist and conformational rigidity in imidazo[1,2-a]pyridines to achieve dual-state emissive (DSE) luminogens for applications in OLEDs and cell-imaging†","authors":"Chinmay Thakkar, Seemantini Kale, Mohammad Amir Ahemad, Monalisa Debnath, Anjali Tripathi, Saona Seth, Purav Badani, Rohit Srivastava, Sangita Bose and Satyajit Saha","doi":"10.1039/D5TC01128K","DOIUrl":"https://doi.org/10.1039/D5TC01128K","url":null,"abstract":"<p >The need for fluorophores that could be emissive in both solution and solid states has led to the development of dual state emissive (DSE) materials, which bridge the gap between the ACQ and AIE and offer omnipresent emission. However, designing DSEgens requires a meticulous balance of the emissive and non-radiative pathways in both states. Despite some advancements, achieving dual-state emission deals with challenges in synthesis, scalability, and application. This study focuses on balancing the molecular twist and electronic rigidity to design DSE molecules using imidazo[1,2-<em>a</em>]pyridine scaffolds, aiming at enhancing emission performance in the solid and solution states. Six novel D–A-structured imidazo[1,2-<em>a</em>]pyridine–arylketone conjugates (<strong>SK-1</strong> to <strong>SK-6</strong>) were synthesized, incorporating bulky aryl rotors like triphenylamine (TPA) and aryl ketones (–COPh) to achieve twisted configurations and impact electronic structures. Experimental results showed promising features, with <strong>SK-3</strong> and <strong>SK-4</strong> displaying DSE effects and <strong>SK-2</strong> and <strong>SK-5</strong> exhibiting AIE characteristics with good PLQY values. The luminogens demonstrated high thermal stabilities, stable electrochemical properties, and effective cell imaging capabilities with low cytotoxicity. The calculated Δ<em>E</em><small>_ST</small> values and lifetimes of prompt/delayed components feature the potential TADF properties of these luminogens. Furthermore, as a proof of concept, <strong>SK-3</strong> and <strong>SK-4</strong> were successfully used in OLED device fabrication. <strong>SK-4</strong> shows a good EQE<small>_max</small> of ∼10.00%, while <strong>SK-3</strong> shows a reasonable EQE<small>_max</small> of ∼6.4% with superior efficiency roll-off as compared to <strong>SK-4</strong>. This study highlighted the importance of balancing molecular distortion and conjugation in designing multifunctional DSE molecules for optoelectronics and bioimaging applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10576-10591"},"PeriodicalIF":5.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient near-infrared luminescence in a Na2CaTi2Ge3O12:Cr3+ garnet for light-emitting-diode applications†","authors":"Yi Xu, Xuewan Lin and Jiyou Zhong","doi":"10.1039/D5TC01230A","DOIUrl":"https://doi.org/10.1039/D5TC01230A","url":null,"abstract":"<p >Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) have emerged as ideal light sources for a variety of advanced spectroscopy applications, demonstrating the importance of developing efficient NIR phosphors. In this work, a Ti<small>⁴⁺</small>-containing garnet, Na<small>₂</small>CaTi<small>₂</small>Ge<small>₃</small>O<small>₁₂</small>, was selected as the host material to minimize the ionic size mismatch after Cr<small>³⁺</small> substitution. Interestingly, this substitution generates charge self-balance, enabling excellent efficiency of the developed material. Under 465 nm excitation, it exhibits broadband emission covering the first NIR window (<em>λ</em><small>_em,max</small> = 790 nm) with a full width at half maximum (FWHM) of 120 nm. The optimized sample achieved a photoluminescence quantum yield (PLQY) of 75%. Moreover, a NIR pc-LED device was fabricated by combining the optimized phosphor with a blue (<em>λ</em><small>_em</small> = 455 nm) InGaN chip. Upon application of a driving current of 100 mA, the device demonstrated a NIR output power of 18.24 mW and a corresponding NIR photoelectronic conversion efficiency of 6.49% and exhibited excellent performance in biological tissue imaging and non-destructive testing. Therefore, this work provides an efficient NIR phosphor, which has promising potential in spectroscopy applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10390-10398"},"PeriodicalIF":5.7,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimode luminescence and highly anti-thermal quenching in Sb3+/Yb3+/Pr3+ Co-doped Cs2NaYCl6 double perovskites†","authors":"Ruoxuan Wang, Chujun Tan, Haowen Hou, Haiyan Wang, Bingsuo Zou and Ruosheng Zeng","doi":"10.1039/D5TC00692A","DOIUrl":"https://doi.org/10.1039/D5TC00692A","url":null,"abstract":"<p >Double perovskites have become a research hotspot in the field of optoelectronic materials due to their environmental friendliness and structural tunability. However, double perovskites with multimode luminescence and thermal stability are still urgently desired for multifunctional fluorescence applications. In this study, yttrium-based double perovskites (Cs<small>₂</small>NaYCl<small>₆</small>) were successfully synthesized by a solvothermal method. The introduction of Yb<small>³⁺</small> and Pr<small>³⁺</small> ions enables down-shifting luminescence modulation as well as the extension of the luminescence range under 340 nm excitation, and bright up-conversion luminescence is observed under 980 nm near-infrared laser excitation. Interestingly, both the down-shifting emission of Yb<small>³⁺</small> ions and the up-conversion emission of Pr<small>³⁺</small> ions show excellent anti-thermal quenching behavior with increasing temperature, which may be attributed to the fact that the inner 4f electrons of lanthanide ions are less affected by temperature. In particular, the relative sensitivity of an optical temperature sensor based on the fluorescence intensity ratio is as high as 6.72% K<small>⁻¹</small>, which could be the highest value reported. Double perovskites combining multimode emission with anti-thermal quenching provide new materials for advanced applications.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 20","pages":" 10072-10079"},"PeriodicalIF":5.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetocaloric effect in Mn-rich Heusler-derived alloys for room temperature-based applications†","authors":"Nishant Tiwari, Subhendu Mishra, Suman Sarkar, Saikat Talapatra, Mithun Palit, Manas Paliwal, Abhishek K. Singh and Chandra Sekhar Tiwary","doi":"10.1039/D4TC04242E","DOIUrl":"https://doi.org/10.1039/D4TC04242E","url":null,"abstract":"<p >Magnetic refrigeration-based technologies rely on the magnetocaloric properties of materials and are crucial for improving energy efficiency and for supporting clean environments. However, materials possessing significant magnetocaloric properties that can be used for room temperature-based applications are still lacking. Heusler alloys (such as Mn–Ni–Ga) show giant magnetocaloric effects, which can be further improved by tuning their composition. Herein, we optimized the ratio of Ni to Ga to achieve an alloy with unique magnetocaloric properties. The alloy demonstrated a substantial magnetocaloric effect, attributed to its narrow temperature range for structural and magnetic phase transitions (near room temperature with minimal hysteresis). Structural phase changes were also observed through high-resolution transmission electron microscopy. Optimum entropy changes, calculated from isothermal magnetization curves (4 Tesla magnetic field), were found to be 24.50 J kg<small>⁻¹</small> K<small>⁻¹</small>, which is higher than that of state-of-the-art alloys. Experimental demonstration of the magnetocaloric effect (refrigeration cycle) was also carried out using a thermal imaging camera. Furthermore, first-principles calculations were conducted to validate the experimental findings, specifically focusing on the compositional effects on the structural transitions and magnetic properties of the investigated MNG alloys.</p>","PeriodicalId":84,"journal":{"name":"Journal of Materials Chemistry C","volume":" 21","pages":" 10789-10803"},"PeriodicalIF":5.7,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}