Novel two-dimensional thermoelectric materials have attracted significant attention in the field of thermoelectric due to their low lattice thermal conductivity.A comprehensive understanding of their microscopic struc...Novel two-dimensional thermoelectric materials have attracted significant attention in the field of thermoelectric due to their low lattice thermal conductivity.A comprehensive understanding of their microscopic structures is crucial for driving further the optimization of materials properties and developing novel functional materials.Here,by using in situ scanning tunneling microscopy,we report the atomic layer evolution and surface reconstruction on the cleaved thermoelectric material KCu_(4)Se_(3) for the first time.We clearly revealed each atomic layer,including the naturally cleaved K atomic layer,the intermediate Se^(2-)atomic layer,and the Se^(-)atomic layer that emerges in the thermodynamic-stable state.Departing from the maj ority of studies that predominantly concentrate on macroscopic measurements of the charge transport,our results reveal the coexistence of potassium disorder and complex reconstructed patterns of selenium,which potentially influences charge carrier and lattice dynamics.These results provide direct insight into the surface microstructures and evolution of KCu_(4)Se_(3),and shed useful light on designing functional materials with superior performance.展开更多
We demonstrate a home-built electrochemical scanning tunneling microscope （ECSTM）. The ECSTM exhibits highly stable performance. The drifting rates in XY and Z directions of the ECSTM are about 67 and 55.6 pm/min, r...We demonstrate a home-built electrochemical scanning tunneling microscope （ECSTM）. The ECSTM exhibits highly stable performance. The drifting rates in XY and Z directions of the ECSTM are about 67 and 55.6 pm/min, respectively. Moreover, a specially designed scanner unit successfully solves the well-known problem of large leakage current in high humidity atmosphere. The mechanical structure of the ECSTM is described in detail. The excellent performances of the system are demonstrated by the measured STM images （in copper sulfate solution）, including clean and well-ordered large area morphology of Au（111） and the atomically resolved image of highly oriented pyrolytic graphite.展开更多
We present the design and performance of a home-built scanning tunneling microscope （STM）, which is compact （66 mm tall and 25 mm in diameter）, yet equipped with a 3D atomic precision piezoelectric motor in which ...We present the design and performance of a home-built scanning tunneling microscope （STM）, which is compact （66 mm tall and 25 mm in diameter）, yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker （of our own invention） driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube （PST） with its brim laying at on the PST end as the inertial slider （driven by the PST） for the XZ （sample plane） motion. The STM is designed to be capable of searching rare microscopic targets （defects, dopants, boundaries, nano-devices, etc.） in a macroscopic sample area （square millimeters） under extreme conditions （low temperatures, strong magnetic elds, etc.） in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.展开更多
The influence of vibration is already one of main obstacles for improving the nano measuring accuracy.The techniques of anti-vibration,vibration isolation and vibration compensation become an important branch in nano ...The influence of vibration is already one of main obstacles for improving the nano measuring accuracy.The techniques of anti-vibration,vibration isolation and vibration compensation become an important branch in nano measuring field.Starting with the research of sensitivity to vibration of scanning tunneling microscope(STM),the theory,techniques and realization methods of nano vibration sensor based on tunnel effect are initially investigated,followed by developing the experimental devices.The experiments of the vibration detection and vibration compensation are carried out.The experimental results show that vibration sensor based on tunnel effect is characterized by high sensitivity,good frequency characteristic and the same vibratory response characteristic consistent with STM.展开更多
We present a homebuilt scanning tunneling microscope(STM)which employs an inner-wall polished sapphire guiding tube as a rail for the scanner to form a short tip-sample mechanical loop.The scanner is mounted on a squa...We present a homebuilt scanning tunneling microscope(STM)which employs an inner-wall polished sapphire guiding tube as a rail for the scanner to form a short tip-sample mechanical loop.The scanner is mounted on a square rod which is housed in the guiding tube and held by a spring strip.The stiff sapphire guiding tube allows the STM body to be made in a simple,compact and rigid form.Also the material of sapphire improves the thermal stability of the STM for its good thermal conductivity.To demonstrate the performance of the STM,high quality atomic-resolution STM images of high oriented pyrolytic graphite were given.展开更多
Nanocrystalline CdSe thin film prepared by chemical solution deposition was imaged in air with a scanning tunnelling microscope(STM). Scanning tunnelling current spectroscopy(STS) was taken at a fixed tip - sample sep...Nanocrystalline CdSe thin film prepared by chemical solution deposition was imaged in air with a scanning tunnelling microscope(STM). Scanning tunnelling current spectroscopy(STS) was taken at a fixed tip - sample separation. Tunnelling current(i) - voltage(v) curve and differential conductance spectrum show an n-type schottky rectifying behaviour and yield a direct measure of band gap energy. An increase of bandgap energy (1.8 - 2.1eV) was measured indicating energy quantization of this particular thin film.,展开更多
This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotationa...This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotational domains of RuO2（110） rotated by an angle of 120°. The as-grown RuO2（110） thin layer is expanded from the bulk-truncated RuO2（110） due to the large mismatch between RuO2（110） and the Ru（0001） substrate. The results also indicate that growth of RuO2（110） thin layer on the Ru（0001） substrate by oxidation tends first to formation of the Ru-O （oxygen） chains in the [001] direction of RuO2 （110）.展开更多
A nover technique for the fabrication of the tip for e tectrochemical scanning tunneting microscopy(ECSTM)is presented. The curvature radius of the fabricated tip is smatter than 1 μM. Faradaic leakage current is tes...A nover technique for the fabrication of the tip for e tectrochemical scanning tunneting microscopy(ECSTM)is presented. The curvature radius of the fabricated tip is smatter than 1 μM. Faradaic leakage current is tess than 0.1nA in the sotution of 1 mol/L NaCl. The atomic image of highty oriented pyrotytic graphite (HOPG)has been taken using the prepared tip.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12374196,92165201,11634011,and 22109153)the Innovation Program for Quantum Science and Technology (Grant No.2021ZD0302800)+4 种基金the CAS Project for Young Scientists in Basic Research (Grant No.YSBR-046)the Fundamental Research Funds for the Central Universities (Grant Nos.WK3510000006 and WK3430000003)the Fund of Anhui Initiative in Quantum Information Technologies (Grant No.AHY170000)the University Synergy Innovation Program of Anhui Province,China (Grant No.GXXT-2022-008)the National Synchrotron Radiation Laboratory Joint Funds of University of Science and Technology of China (Grant No.KY2060000241)。
文摘Novel two-dimensional thermoelectric materials have attracted significant attention in the field of thermoelectric due to their low lattice thermal conductivity.A comprehensive understanding of their microscopic structures is crucial for driving further the optimization of materials properties and developing novel functional materials.Here,by using in situ scanning tunneling microscopy,we report the atomic layer evolution and surface reconstruction on the cleaved thermoelectric material KCu_(4)Se_(3) for the first time.We clearly revealed each atomic layer,including the naturally cleaved K atomic layer,the intermediate Se^(2-)atomic layer,and the Se^(-)atomic layer that emerges in the thermodynamic-stable state.Departing from the maj ority of studies that predominantly concentrate on macroscopic measurements of the charge transport,our results reveal the coexistence of potassium disorder and complex reconstructed patterns of selenium,which potentially influences charge carrier and lattice dynamics.These results provide direct insight into the surface microstructures and evolution of KCu_(4)Se_(3),and shed useful light on designing functional materials with superior performance.
文摘We demonstrate a home-built electrochemical scanning tunneling microscope （ECSTM）. The ECSTM exhibits highly stable performance. The drifting rates in XY and Z directions of the ECSTM are about 67 and 55.6 pm/min, respectively. Moreover, a specially designed scanner unit successfully solves the well-known problem of large leakage current in high humidity atmosphere. The mechanical structure of the ECSTM is described in detail. The excellent performances of the system are demonstrated by the measured STM images （in copper sulfate solution）, including clean and well-ordered large area morphology of Au（111） and the atomically resolved image of highly oriented pyrolytic graphite.
文摘We present the design and performance of a home-built scanning tunneling microscope （STM）, which is compact （66 mm tall and 25 mm in diameter）, yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker （of our own invention） driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube （PST） with its brim laying at on the PST end as the inertial slider （driven by the PST） for the XZ （sample plane） motion. The STM is designed to be capable of searching rare microscopic targets （defects, dopants, boundaries, nano-devices, etc.） in a macroscopic sample area （square millimeters） under extreme conditions （low temperatures, strong magnetic elds, etc.） in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.
文摘The influence of vibration is already one of main obstacles for improving the nano measuring accuracy.The techniques of anti-vibration,vibration isolation and vibration compensation become an important branch in nano measuring field.Starting with the research of sensitivity to vibration of scanning tunneling microscope(STM),the theory,techniques and realization methods of nano vibration sensor based on tunnel effect are initially investigated,followed by developing the experimental devices.The experiments of the vibration detection and vibration compensation are carried out.The experimental results show that vibration sensor based on tunnel effect is characterized by high sensitivity,good frequency characteristic and the same vibratory response characteristic consistent with STM.
基金supported by the National Key RD Program of China (No.2017YFA0402903 and No.2016YFA0401003)National Natural Science Foundation of China (No.21505139, No.51627901,and No.11374278)+1 种基金Chinese Academy of Sciences Scientific Research Equipment (No.YZ201628)National Science Foundation for Young Scientists of China (No.11504339)
文摘We present a homebuilt scanning tunneling microscope(STM)which employs an inner-wall polished sapphire guiding tube as a rail for the scanner to form a short tip-sample mechanical loop.The scanner is mounted on a square rod which is housed in the guiding tube and held by a spring strip.The stiff sapphire guiding tube allows the STM body to be made in a simple,compact and rigid form.Also the material of sapphire improves the thermal stability of the STM for its good thermal conductivity.To demonstrate the performance of the STM,high quality atomic-resolution STM images of high oriented pyrolytic graphite were given.
文摘Nanocrystalline CdSe thin film prepared by chemical solution deposition was imaged in air with a scanning tunnelling microscope(STM). Scanning tunnelling current spectroscopy(STS) was taken at a fixed tip - sample separation. Tunnelling current(i) - voltage(v) curve and differential conductance spectrum show an n-type schottky rectifying behaviour and yield a direct measure of band gap energy. An increase of bandgap energy (1.8 - 2.1eV) was measured indicating energy quantization of this particular thin film.,
基金Project supported by the National Natural Science Foundation of China （Grant No 10274072）, and the Specialized Research Fund for the Doctoral Program of Higher Education of China （Grant No 20030335017）.
文摘This paper reports that the growth of RuO2（110） thin layer growth on Ru（0001） has been investigated by means of scanning tunnelling microscope （STM）. The STM images showed a domain structure with three rotational domains of RuO2（110） rotated by an angle of 120°. The as-grown RuO2（110） thin layer is expanded from the bulk-truncated RuO2（110） due to the large mismatch between RuO2（110） and the Ru（0001） substrate. The results also indicate that growth of RuO2（110） thin layer on the Ru（0001） substrate by oxidation tends first to formation of the Ru-O （oxygen） chains in the [001] direction of RuO2 （110）.
文摘A nover technique for the fabrication of the tip for e tectrochemical scanning tunneting microscopy(ECSTM)is presented. The curvature radius of the fabricated tip is smatter than 1 μM. Faradaic leakage current is tess than 0.1nA in the sotution of 1 mol/L NaCl. The atomic image of highty oriented pyrotytic graphite (HOPG)has been taken using the prepared tip.
