The crystallographic and magnetic properties are presented for van der Waals antiferromagnetic FePS_3. High-quality single crystals of millimeter size have been successfully synthesized through the chemical vapor tran...The crystallographic and magnetic properties are presented for van der Waals antiferromagnetic FePS_3. High-quality single crystals of millimeter size have been successfully synthesized through the chemical vapor transport method. The layered structure and cleavability of the compound are apparent, which are beneficial for a potential exploration of the interesting low dimensional magnetism, as well as for incorporation of FePS_3 into van der Waals heterostructures. For the sake of completeness, we have measured both direct current(dc) and alternating current(ac) magnetic susceptibility.The paramagnetic to antiferromagnetic transition occurs at approximately T_N 115 K. The effective moment is larger than the spin-only effective moment, suggesting that an orbital contribution to the total angular momentum of the Fe^(2+) could be present. The ac susceptibility is independent of frequency, which means that the spin freezing effect is excluded.Strong anisotropy of out-of-plane and in-plane susceptibility has been shown, demonstrating the Ising-type magnetic order in FePS_3 system.展开更多
Two-dimensional(2D)nanomaterials have emerged as highly efficient co-catalysts in the field of photocatalytic water splitting,due to their distinct physicochemical features.Herein,a novel 2D nanomaterial,ultrathin FeP...Two-dimensional(2D)nanomaterials have emerged as highly efficient co-catalysts in the field of photocatalytic water splitting,due to their distinct physicochemical features.Herein,a novel 2D nanomaterial,ultrathin FePS_(3)nanosheets,is prepared by an ultrasoundassisted delamination process in organic solvent,followed by the in situ construction of CdS nanosheet/FePS_(3)nanosheet hierarchical heterojunction via the solvothermal method.It is notable that the designed CdS/FePS_(3)photocatalyst demonstrates an efficient hydrogen-producing performance up to 7565μmol g^(-1)h^(-1)for hydrogen production reaction(HER)under visible-light illumination,which is almost 8 times higher than that of bulk CdS.The enhancement in HER performance is attributed to the synergy of accelerated interfacial charge transfer,high specific surface area,and extended visible-light absorption originating from as-synthesized conductive few-layer FePS_(3)nanosheets.Furthermore,the charge transfer pathway of the constructed 2D CdS/2D FePS_(3)heterojunction is unveiled by in situ atomic force microscopy with Kelvin probe force microscopy(AFM-KPFM),in situ X-ray photoelectron spectroscopy(XPS),and photoelectrochemical measurements.This study offers new insight into the rational design and controllable synthesis of FePS_(3-)based composite photocatalytic systems for efficient photocatalytic hydrogen production.展开更多
A new intercalation compound,Fe_(0.85)PS_(3)(4,4-bipyH)_(0.30)(4,4-bipy=4,4-bipyridine),is obtained by the intercalation of 4,4-bipyridine-2HCl with lamellar FePS_(3),which is characterized by elemental analysis,powde...A new intercalation compound,Fe_(0.85)PS_(3)(4,4-bipyH)_(0.30)(4,4-bipy=4,4-bipyridine),is obtained by the intercalation of 4,4-bipyridine-2HCl with lamellar FePS_(3),which is characterized by elemental analysis,powder X-ray diffraction,infrared spectroscopy.By comparison with the pure FePS_(3),the lattice spacing of Fe0.85PS_(3)(4,4-bipyH)0.30 is expanded by~5.7,indicating that the ring plane of the vip is perpendicular to the layer of the host.The magnetic property of Fe0.85PS_(3)(4,4-bipyH)0.30 is studied with SQUID.It exhibits an antiferromagnetic phase transition with TN of about 70 K.展开更多
Van der Waals(vdW)crystals,particularly transition metal phosphorus trisulfides(MPX_(3)),have garnered significant attention because of their tunable magnetic properties through intercalation.This study investigated t...Van der Waals(vdW)crystals,particularly transition metal phosphorus trisulfides(MPX_(3)),have garnered significant attention because of their tunable magnetic properties through intercalation.This study investigated the magnetic behavior of FePS_(3) intercalated with cobaltecene ions(FePS_(3)(CoCp_(2))_(0.40)),focusing on its negative magnetization(NM)and exchange bias(EB)effects.Structural analysis reveals an expansion of the interlayer spacing from 6.46Å to 11.95Å and the emergence of spontaneous magnetization below 65 K.A robust NM is observed below~35 K under zero-field cooling(ZFC),even at high magnetic fields.Detailed investigations demonstrate that this ZFC-NM arises from a combination of a negative trapped field in the superconducting magnet and the material’s giant coercive force rather than an intrinsic magnetic mechanism.Furthermore,the apparent EB effect,often misinterpreted as intrinsic,is attributed to a secondary minorloop effect rather than genuine EB.By systematically excluding external influences,the study confirms that FePS3(CoCp_(2))_(0.40) has no intrinsic NM or EB.This work provides a critical methodology to distinguish extrinsic from intrinsic magnetic phenomena in high-coercivity materials,advancing the understanding of vdW magnetism and its applications in spintronic devices.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404169,51602159,and 11704196)the Scientific Research Foundation of Nanjing University of Posts&Telecommunications,China(Grant Nos.NY217043 and NY218021)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant Nos.KYCX17 0754 and SJCX18 0287)
文摘The crystallographic and magnetic properties are presented for van der Waals antiferromagnetic FePS_3. High-quality single crystals of millimeter size have been successfully synthesized through the chemical vapor transport method. The layered structure and cleavability of the compound are apparent, which are beneficial for a potential exploration of the interesting low dimensional magnetism, as well as for incorporation of FePS_3 into van der Waals heterostructures. For the sake of completeness, we have measured both direct current(dc) and alternating current(ac) magnetic susceptibility.The paramagnetic to antiferromagnetic transition occurs at approximately T_N 115 K. The effective moment is larger than the spin-only effective moment, suggesting that an orbital contribution to the total angular momentum of the Fe^(2+) could be present. The ac susceptibility is independent of frequency, which means that the spin freezing effect is excluded.Strong anisotropy of out-of-plane and in-plane susceptibility has been shown, demonstrating the Ising-type magnetic order in FePS_3 system.
基金financially supported by the Science Fund for Distinguished Young Scholars,Nanjing Forestry University(No.JC2019002)
文摘Two-dimensional(2D)nanomaterials have emerged as highly efficient co-catalysts in the field of photocatalytic water splitting,due to their distinct physicochemical features.Herein,a novel 2D nanomaterial,ultrathin FePS_(3)nanosheets,is prepared by an ultrasoundassisted delamination process in organic solvent,followed by the in situ construction of CdS nanosheet/FePS_(3)nanosheet hierarchical heterojunction via the solvothermal method.It is notable that the designed CdS/FePS_(3)photocatalyst demonstrates an efficient hydrogen-producing performance up to 7565μmol g^(-1)h^(-1)for hydrogen production reaction(HER)under visible-light illumination,which is almost 8 times higher than that of bulk CdS.The enhancement in HER performance is attributed to the synergy of accelerated interfacial charge transfer,high specific surface area,and extended visible-light absorption originating from as-synthesized conductive few-layer FePS_(3)nanosheets.Furthermore,the charge transfer pathway of the constructed 2D CdS/2D FePS_(3)heterojunction is unveiled by in situ atomic force microscopy with Kelvin probe force microscopy(AFM-KPFM),in situ X-ray photoelectron spectroscopy(XPS),and photoelectrochemical measurements.This study offers new insight into the rational design and controllable synthesis of FePS_(3-)based composite photocatalytic systems for efficient photocatalytic hydrogen production.
基金the National Natural Science Foundation of China for financial support.
文摘A new intercalation compound,Fe_(0.85)PS_(3)(4,4-bipyH)_(0.30)(4,4-bipy=4,4-bipyridine),is obtained by the intercalation of 4,4-bipyridine-2HCl with lamellar FePS_(3),which is characterized by elemental analysis,powder X-ray diffraction,infrared spectroscopy.By comparison with the pure FePS_(3),the lattice spacing of Fe0.85PS_(3)(4,4-bipyH)0.30 is expanded by~5.7,indicating that the ring plane of the vip is perpendicular to the layer of the host.The magnetic property of Fe0.85PS_(3)(4,4-bipyH)0.30 is studied with SQUID.It exhibits an antiferromagnetic phase transition with TN of about 70 K.
基金supported by the National Key Research and Development Program of China(2023YFA1610100)HFNL Self-Deployed Project(ZB2025020100)the National Natural Science Foundation of China(51627901).
文摘Van der Waals(vdW)crystals,particularly transition metal phosphorus trisulfides(MPX_(3)),have garnered significant attention because of their tunable magnetic properties through intercalation.This study investigated the magnetic behavior of FePS_(3) intercalated with cobaltecene ions(FePS_(3)(CoCp_(2))_(0.40)),focusing on its negative magnetization(NM)and exchange bias(EB)effects.Structural analysis reveals an expansion of the interlayer spacing from 6.46Å to 11.95Å and the emergence of spontaneous magnetization below 65 K.A robust NM is observed below~35 K under zero-field cooling(ZFC),even at high magnetic fields.Detailed investigations demonstrate that this ZFC-NM arises from a combination of a negative trapped field in the superconducting magnet and the material’s giant coercive force rather than an intrinsic magnetic mechanism.Furthermore,the apparent EB effect,often misinterpreted as intrinsic,is attributed to a secondary minorloop effect rather than genuine EB.By systematically excluding external influences,the study confirms that FePS3(CoCp_(2))_(0.40) has no intrinsic NM or EB.This work provides a critical methodology to distinguish extrinsic from intrinsic magnetic phenomena in high-coercivity materials,advancing the understanding of vdW magnetism and its applications in spintronic devices.
