A new compound with one-dimensional spin chains, Ba9Co3Se(15), was synthesized under high pressure and high temperature conditions and systematically characterized via structural, transport and magnetic measurements. ...A new compound with one-dimensional spin chains, Ba9Co3Se(15), was synthesized under high pressure and high temperature conditions and systematically characterized via structural, transport and magnetic measurements. Ba9Co3Se(15) crystallizes in a hexagonal structure with the space group P-6c2(No. 188) and lattice constants of a = b = 9.6765 ? and c = 18.9562 ?. The structure consists of trimeric face-sharing octahedral CoSe6 chains, which are arranged in a triangular lattice in the ab-plane and separated by Ba atoms. The distance of the nearest neighbor of CoSe6 chains is very large, given by the lattice constant a = 9.6765 ?. The Weiss temperature Tθ associated with the intra-chain coupling strength is about -346 K. However, no long-range magnetic order but a spin glass transition at ~ 3 K has been observed. Our results indicate that the spin glass behavior in Ba9Co3Se(15) mainly arises from the magnetic frustration due to the geometrically frustrated triangular lattice.展开更多
We further calculate the dependence of xT on T in high magnetic fields,where X denotes susceptibility and T is temperature,using our previous research work - Green function's decoupling approximate approach,for th...We further calculate the dependence of xT on T in high magnetic fields,where X denotes susceptibility and T is temperature,using our previous research work - Green function's decoupling approximate approach,for the one-dimensional ferrimagnetic chain with alternating spins 1 and 1/2.We find a linear correlation in certain range of magnetic field between the temperature of xT maximum and the magnetic field.Moreover,we simply analyze its physical meaning by our approach.展开更多
A series of samples of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15)(x=0,0.05,0.1,0.15,0.2)with quasi-one-dimensional(1D)structure were successfully synthesized under high-temperature and high-pressure conditions.The influence of ...A series of samples of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15)(x=0,0.05,0.1,0.15,0.2)with quasi-one-dimensional(1D)structure were successfully synthesized under high-temperature and high-pressure conditions.The influence of partial substitution of S for Se on the structure,electronic transport,and magnetic properties of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15) has been investigated in detail.The x-ray diffraction data shows that the lattice constant decreases linearly with increasing S-doping level,which follows the Vegrad’s law.The doped S atoms preferentially occupy the site of Se atoms in CoSe6 octahedron.Physical properties measurements indicate that all the samples of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15) are semiconducting and display spin glass behavior.As the replacement of Se by smaller size S,although the inter-chain distance decreases,the electronic hopping between CoSe/S6 chains is weakened and leads to an increase of band gap from 0.75 eV to 0.86 eV,since the S-3p electrons are more localized than Se-4p ones.Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15) exhibits 1D conducting chain characteristic.展开更多
One-dimensional mono- or few-atomic chains were successfully fabricated in a variety of two-dimensional materials, like graphene, BN, and transition metal dichalcogenides, which exhibit striking transport and mechanic...One-dimensional mono- or few-atomic chains were successfully fabricated in a variety of two-dimensional materials, like graphene, BN, and transition metal dichalcogenides, which exhibit striking transport and mechanical properties. How- ever, atomic chains of black phosphorus （BP）, an emerging electronic and optoelectronic material, is yet to be investigated. Here, we comprehensively considered the geometry stability of six categories of infinite BP atomic chains, transitions among them, and their electronic structures. These categories include mono- and dual-atomic linear, armchair, and zigzag chains. Each zigzag chain was found to be the most stable in each category with the same chain width. The mono-atomic zigzag chain was predicted as a Dirac semi-metal. In addition, we proposed prototype structures of suspended and sup- ported finite atomic chains. It was found that the zigzag chain is, again, the most stable form and could be transferred from mono-atomic armchair chains. An orientation dependence was revealed for supported armchair chains that they prefer an angle of roughly 35°-37° perpendicular to the BP edge, corresponding to the [110] direction of the substrate BP sheet. These results may promote successive research on mono- or few-atomic chains of BP and other two-dimensional materials for unveiling their unexplored physical properties.展开更多
Due to the influence of quantum confinementeffect, two-dimensional (2D) materials like graphene exhibitunique and exceptional properties, highlighting the significance of low-dimensional materials in fundamental resea...Due to the influence of quantum confinementeffect, two-dimensional (2D) materials like graphene exhibitunique and exceptional properties, highlighting the significance of low-dimensional materials in fundamental research and practical applications. This has led to highexpectations for one-dimensional (1D) atomic chain materialswith even lower dimensions. Compared with 2D materials,single 1D atomic chains reach their physical limits in bothdimensions, resulting in a more pronounced quantum confinement effect that gives rise to unexpected physical phenomena and will establish a new field for exploration. Herein,we review the emerging field concerning 1D van der Waals(vdW) atomic chains. We first summarize the various typesand structures of their bulk of the 1D vdW materials. Subsequently,we discuss the methods employed for their preparation and characterization. Finally, we analyze the challengesfaced during the development of 1D atomic chains and provide prospects for their future development.展开更多
基金Project supported by the National Key R&D Program of China and the National Natural Science Foundation of China(Grant Nos.2018YFA0305700,2017YFA0302900,11974410,and 11534016)。
文摘A new compound with one-dimensional spin chains, Ba9Co3Se(15), was synthesized under high pressure and high temperature conditions and systematically characterized via structural, transport and magnetic measurements. Ba9Co3Se(15) crystallizes in a hexagonal structure with the space group P-6c2(No. 188) and lattice constants of a = b = 9.6765 ? and c = 18.9562 ?. The structure consists of trimeric face-sharing octahedral CoSe6 chains, which are arranged in a triangular lattice in the ab-plane and separated by Ba atoms. The distance of the nearest neighbor of CoSe6 chains is very large, given by the lattice constant a = 9.6765 ?. The Weiss temperature Tθ associated with the intra-chain coupling strength is about -346 K. However, no long-range magnetic order but a spin glass transition at ~ 3 K has been observed. Our results indicate that the spin glass behavior in Ba9Co3Se(15) mainly arises from the magnetic frustration due to the geometrically frustrated triangular lattice.
文摘We further calculate the dependence of xT on T in high magnetic fields,where X denotes susceptibility and T is temperature,using our previous research work - Green function's decoupling approximate approach,for the one-dimensional ferrimagnetic chain with alternating spins 1 and 1/2.We find a linear correlation in certain range of magnetic field between the temperature of xT maximum and the magnetic field.Moreover,we simply analyze its physical meaning by our approach.
基金supported by the Doctoral Fund of Henan University of Technology(Grant No.2020BS029)the National Key R&D Program of China(Grant Nos.2018YFA0305700 and 2017YFA0302900)+1 种基金the National Natural Science Foundation of China(Grant Nos.11974410 and 11820101003)the Stable Support Plan Program of Shenzhen Natural Science Fund(Grant No.20200925152415003)。
文摘A series of samples of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15)(x=0,0.05,0.1,0.15,0.2)with quasi-one-dimensional(1D)structure were successfully synthesized under high-temperature and high-pressure conditions.The influence of partial substitution of S for Se on the structure,electronic transport,and magnetic properties of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15) has been investigated in detail.The x-ray diffraction data shows that the lattice constant decreases linearly with increasing S-doping level,which follows the Vegrad’s law.The doped S atoms preferentially occupy the site of Se atoms in CoSe6 octahedron.Physical properties measurements indicate that all the samples of Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15) are semiconducting and display spin glass behavior.As the replacement of Se by smaller size S,although the inter-chain distance decreases,the electronic hopping between CoSe/S6 chains is weakened and leads to an increase of band gap from 0.75 eV to 0.86 eV,since the S-3p electrons are more localized than Se-4p ones.Ba_(9)Co_(3)(Se_(1−x)S_(x))_(15) exhibits 1D conducting chain characteristic.
基金Project supported by the National Natural Science Foundation of China(Gant Nos.11274380,91433103,11622437,and 61674171)the Fundamental Research Funds for the Central Universities,China+1 种基金the Research Funds of Renmin University of China(Grant No.16XNLQ01)supported by the Outstanding Innovative Talents Cultivation Funded Programs 2016 of Renmin University of China
文摘One-dimensional mono- or few-atomic chains were successfully fabricated in a variety of two-dimensional materials, like graphene, BN, and transition metal dichalcogenides, which exhibit striking transport and mechanical properties. How- ever, atomic chains of black phosphorus （BP）, an emerging electronic and optoelectronic material, is yet to be investigated. Here, we comprehensively considered the geometry stability of six categories of infinite BP atomic chains, transitions among them, and their electronic structures. These categories include mono- and dual-atomic linear, armchair, and zigzag chains. Each zigzag chain was found to be the most stable in each category with the same chain width. The mono-atomic zigzag chain was predicted as a Dirac semi-metal. In addition, we proposed prototype structures of suspended and sup- ported finite atomic chains. It was found that the zigzag chain is, again, the most stable form and could be transferred from mono-atomic armchair chains. An orientation dependence was revealed for supported armchair chains that they prefer an angle of roughly 35°-37° perpendicular to the BP edge, corresponding to the [110] direction of the substrate BP sheet. These results may promote successive research on mono- or few-atomic chains of BP and other two-dimensional materials for unveiling their unexplored physical properties.
基金supported by the National Natural Science Foundation of China (22175184 and 22105207)the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research (YSBR053)+1 种基金the Strategic Priority Research Programme of the Chinese Academy of Sciences (XDB0520202)the CAS Project for Young Scientists in Interdisciplinary Research。
文摘Due to the influence of quantum confinementeffect, two-dimensional (2D) materials like graphene exhibitunique and exceptional properties, highlighting the significance of low-dimensional materials in fundamental research and practical applications. This has led to highexpectations for one-dimensional (1D) atomic chain materialswith even lower dimensions. Compared with 2D materials,single 1D atomic chains reach their physical limits in bothdimensions, resulting in a more pronounced quantum confinement effect that gives rise to unexpected physical phenomena and will establish a new field for exploration. Herein,we review the emerging field concerning 1D van der Waals(vdW) atomic chains. We first summarize the various typesand structures of their bulk of the 1D vdW materials. Subsequently,we discuss the methods employed for their preparation and characterization. Finally, we analyze the challengesfaced during the development of 1D atomic chains and provide prospects for their future development.
