Intercalated transition metal dichalcogenides(TMDCs)attract much attention due to their rich properties and potential applications.In this article,we grew successfully high-quality V_(1/3)TaS_(2) crystals by a vapor t...Intercalated transition metal dichalcogenides(TMDCs)attract much attention due to their rich properties and potential applications.In this article,we grew successfully high-quality V_(1/3)TaS_(2) crystals by a vapor transport method.We measured the magnetization,longitudinal resistivityρxx(T,H),Hall resistivityρxy(T,H),as well as performed calculations of the electronic band structure.It was found that V_(1/3)TaS_(2) is an A-type antiferromagnet with the Neel temperature T_(N)=6.20 K,and exhibits a negative magnetoresistance(MR)near T_(N).Both band structure calculations and Hall resistivity measurements demonstrated it is a magnetic semimetal.展开更多
Superconductivity below 0.3 K and a charge-density-wave-like(CDW-like) anomaly at 280 K were observed in EuBiS_(2)F recently.Here we report a systematic study of structural and transport properties in Eu_(0.5)Ln_(0.5)...Superconductivity below 0.3 K and a charge-density-wave-like(CDW-like) anomaly at 280 K were observed in EuBiS_(2)F recently.Here we report a systematic study of structural and transport properties in Eu_(0.5)Ln_(0.5)BiS_(2)F(Ln=La,Ce,Pr,Nd,Sm) by electrical resistivity,magnetization,and specific heat measurements.The lattice constants have a significant change upon rare earth substitution for Eu,suggesting an effective doping.As Ln is changed from Sm to La,the superconducting transition temperature T_(c) increases from 1.55 K to 2.8 K.In contrast to the metallic parent compound,the temperature dependence of electrical resistivity displays semiconductinglike behavior for all the Eu_(0.5)Ln_(0.5)BiS_(2)F samples.Meanwhile,the CDW-like anomaly observed in EuBiS2F is completely suppressed.Unlike the mixed valence state in the undoped compound,Eu ions in these rareearth-doped samples are mainly divalent.A specific anomaly at 1.3 K resembling that in EuBiS_(2)F suggests the coexistence of superconductivity and spin glass state for Eu_(0.5)Ln_(0.5)BiS_(2)F.Coexistence of ferromagnetic order and superconductivity is found below 2.2 K in Eu_(0.5)Ln_(0.5)BiS_(2)F samples.Our results supplies a rich diagram showing that many interesting properties can be induced in BiS_(2)-based compounds.展开更多
Since the discovery of high-temperature superconductivity(SC) in quasi-two-dimensional copper oxides,a few layered compounds,which bear similarities to the cuprates,have also been found to host the unconventional SC. ...Since the discovery of high-temperature superconductivity(SC) in quasi-two-dimensional copper oxides,a few layered compounds,which bear similarities to the cuprates,have also been found to host the unconventional SC. Our recent observation of SC at 6.1 K in correlated electron material K2Cr3As3 represents an obviously different paradigm,primarily because of its quasi-one-dimensional(Q1D) nature. The new material is structurally featured by the [(Cr3As3)2-]∞ double-walled subnano-tubes composed of face-sharing Cr6/2(As6/2) octahedron linear chains,which are well separated by the columns of K+ counterions. Later,an isostructural superconducting Rb2Cr3As3 was synthesized,thus forming a new superconducting family. Here we report the third member,Cs2Cr3As3,which possesses the largest interchain distance. SC appears below 2.2 K. Similar to the former two sister compounds,Cs2Cr3As3 exhibits a non-Fermi liquid behavior with a linear temperature dependence of resistivity in the normal state,and a high upper critical field beyond the Pauli limit as well,suggesting a common unconventional SC in the Q1 D Cr-based material.展开更多
Recently, new Cr-based superconductors, A2Cr3As3(A = K, Rb, Cs), have gained intense interest because of their one-dimensional crystal structures and electron correlations. Here we report the crystal structure and phy...Recently, new Cr-based superconductors, A2Cr3As3(A = K, Rb, Cs), have gained intense interest because of their one-dimensional crystal structures and electron correlations. Here we report the crystal structure and physical properties of two related materials ACr3As3(A = Rb, Cs) which are synthesized via a soft-chemical A+ deintercalation in A2Cr3As3. The new compounds remain one-dimensional(Cr3As3)∞ linear chains, and the interchain distance can be tuned by the incorporation of the alkali-metal cations with different sizes. The physical property measurements indicate a local-moment behavior at high temperatures, and the moments freeze into a cluster spin-glass state below 5–6 K. No superconductivity was observed in both materials. We also found that, with increasing the interchain distance, the Cr effective moments increase monotonically, accompanied with the enhancement of semi-conductivity. Our results shed light on the understanding of occurrence of superconductivity in A2Cr3As3.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1403202)the National Natural Science Foundation of China(Grant Nos.NSFC-12074335,11974095,5177115,11974095,and 12188101)the Natural Science Foundation of Shaanxi Province of China(Grant No.2022JM-028).
文摘Intercalated transition metal dichalcogenides(TMDCs)attract much attention due to their rich properties and potential applications.In this article,we grew successfully high-quality V_(1/3)TaS_(2) crystals by a vapor transport method.We measured the magnetization,longitudinal resistivityρxx(T,H),Hall resistivityρxy(T,H),as well as performed calculations of the electronic band structure.It was found that V_(1/3)TaS_(2) is an A-type antiferromagnet with the Neel temperature T_(N)=6.20 K,and exhibits a negative magnetoresistance(MR)near T_(N).Both band structure calculations and Hall resistivity measurements demonstrated it is a magnetic semimetal.
基金the National Natural Science Foundation of China(Grant No.11704311)the Natural Science Foundation of Shaanxi Provincial Department of Education(Grant No.17JK0772)the Natural Science Foundation of Shaanxi Province(Grant No.2018JQ1069)。
文摘Superconductivity below 0.3 K and a charge-density-wave-like(CDW-like) anomaly at 280 K were observed in EuBiS_(2)F recently.Here we report a systematic study of structural and transport properties in Eu_(0.5)Ln_(0.5)BiS_(2)F(Ln=La,Ce,Pr,Nd,Sm) by electrical resistivity,magnetization,and specific heat measurements.The lattice constants have a significant change upon rare earth substitution for Eu,suggesting an effective doping.As Ln is changed from Sm to La,the superconducting transition temperature T_(c) increases from 1.55 K to 2.8 K.In contrast to the metallic parent compound,the temperature dependence of electrical resistivity displays semiconductinglike behavior for all the Eu_(0.5)Ln_(0.5)BiS_(2)F samples.Meanwhile,the CDW-like anomaly observed in EuBiS2F is completely suppressed.Unlike the mixed valence state in the undoped compound,Eu ions in these rareearth-doped samples are mainly divalent.A specific anomaly at 1.3 K resembling that in EuBiS_(2)F suggests the coexistence of superconductivity and spin glass state for Eu_(0.5)Ln_(0.5)BiS_(2)F.Coexistence of ferromagnetic order and superconductivity is found below 2.2 K in Eu_(0.5)Ln_(0.5)BiS_(2)F samples.Our results supplies a rich diagram showing that many interesting properties can be induced in BiS_(2)-based compounds.
基金supported by the National Natural Science Foundation of China (11190023 and 11474252)the National Basic Research Program of China (2011CBA00103)the Fundamental Research Funds for the Central Universities of China
文摘Since the discovery of high-temperature superconductivity(SC) in quasi-two-dimensional copper oxides,a few layered compounds,which bear similarities to the cuprates,have also been found to host the unconventional SC. Our recent observation of SC at 6.1 K in correlated electron material K2Cr3As3 represents an obviously different paradigm,primarily because of its quasi-one-dimensional(Q1D) nature. The new material is structurally featured by the [(Cr3As3)2-]∞ double-walled subnano-tubes composed of face-sharing Cr6/2(As6/2) octahedron linear chains,which are well separated by the columns of K+ counterions. Later,an isostructural superconducting Rb2Cr3As3 was synthesized,thus forming a new superconducting family. Here we report the third member,Cs2Cr3As3,which possesses the largest interchain distance. SC appears below 2.2 K. Similar to the former two sister compounds,Cs2Cr3As3 exhibits a non-Fermi liquid behavior with a linear temperature dependence of resistivity in the normal state,and a high upper critical field beyond the Pauli limit as well,suggesting a common unconventional SC in the Q1 D Cr-based material.
基金supported by the National Natural Science Foundation of China (11190023 and 11474252)the National Basic Research Program (2011CBA00103)
文摘Recently, new Cr-based superconductors, A2Cr3As3(A = K, Rb, Cs), have gained intense interest because of their one-dimensional crystal structures and electron correlations. Here we report the crystal structure and physical properties of two related materials ACr3As3(A = Rb, Cs) which are synthesized via a soft-chemical A+ deintercalation in A2Cr3As3. The new compounds remain one-dimensional(Cr3As3)∞ linear chains, and the interchain distance can be tuned by the incorporation of the alkali-metal cations with different sizes. The physical property measurements indicate a local-moment behavior at high temperatures, and the moments freeze into a cluster spin-glass state below 5–6 K. No superconductivity was observed in both materials. We also found that, with increasing the interchain distance, the Cr effective moments increase monotonically, accompanied with the enhancement of semi-conductivity. Our results shed light on the understanding of occurrence of superconductivity in A2Cr3As3.
