Thermoelectric Transport Properties of Individual Bismuth Nanowires

2001 ◽  
Vol 691 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu-Ming Lin ◽  
Oded Rabin ◽  
Marcie R. Black ◽  
Gene Dresselhaus ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Point Contacts ◽  
Large Spread ◽  
Thermoelectric Transport Properties ◽  
Bismuth Nanowires ◽  
Increasing Temperature ◽  
Magneto Resistance

ABSTRACTWe developed a method for making 4-point contacts to Bi nanowires with a thick oxide coat using a combination of lithographic and focused ion beam (FIB) techniques. The resistivity of Bi nanowires with diameters in the range 70-200nm is found to increase with decreasing wire diameter. In contrast to bulk Bi, the temperature dependence of the resistivity is found to decrease monotonically with increasing temperature. The results are explained on the basis of increased scattering in the nanowire and the known temperature dependence of the electronic properties of bulk Bi. A large magneto-resistance was also measured, indicating a high crystalline quality of the nanowires. A large spread in the measured values of the resistivity indicates significant systematic error in the measurement technique. Possible sources for error are discussed.

Electronic Properties of Bismuth Nanowires

2001 ◽  
Vol 679 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu-Ming Lin ◽  
Oded Rabin ◽  
Marcie R. Black ◽  
Gene Dresselhaus ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Band Structure ◽  
Temperature Dependence ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Temperature Dependent ◽  
Si Substrates ◽  
Bismuth Nanowires ◽  
Bi Nanowire ◽  
Anodic Alumina Templates

ABSTRACTThe pressure filling of anodic alumina templates with molten bismuth has been used to synthesize single crystalline bismuth nanowires with diameters ranging from 7 to 200nm and lengths of 50μm. The nanowires are separated by dissolving the template, and electrodes are affixed to single Bi nanowires on Si substrates. A focused ion beam (FIB) technique is used first to sputter off the oxide from the nanowires with a Ga ion beam and then to deposit Pt without breaking vacuum. The resistivity of a 200nm diameter Bi nanowire is found to be only slightly greater than the bulk value, while preliminary measurements indicate that the resistivity of a 100nm diameter nanowire is significantly larger than bulk. The temperature dependence of the resistivity of a 100nm nanowire is modeled by considering the temperature dependent band parameters and the quantized band structure of the nanowires. This theoretical model is consistent with the experimental results.

Optimizing Gas-Assisted FIB Processes: The Importance of Oft-Ignored Secondary Parameters

2004 ◽  
Author(s):  
C. Rue ◽  
S. Herschbein ◽  
C. Scrudato ◽  
L. Fischer ◽  
A. Shore
Keyword(s):  
Focused Ion Beam ◽  
Vacuum Chamber ◽  
Ion Beam ◽  
Memory Capacity ◽  
Metal Films ◽  
Deposited Metal ◽  
Influence Process ◽  
Focused Beams ◽  
Gas Pressures

Abstract The efficiency of Gas-Assisted Etching (GAE) and depositions performed using the Focused Ion Beam (FIB) technique is subject to numerous factors. Besides the wellknown primary parameters recommended by the FIB manufacturer (pixel spacing, dwell time, and gas pressures), certain secondary factors can also have a pronounced effect on the quality of these gas-assisted FIB operations. The position of the gas delivery nozzle during XeF2 mills on silicon is examined and was found to affect both the milling speed and the texture on the floor of the FIB trench. Limitations arising from the memory capacity of the FIB computer can also influence process times and trench quality. Exposing the FIB vacuum chamber to TMCTS during SiO2 depositions is found to temporarily impede the performance of subsequent tungsten depositions, especially following heavy or prolonged TMCTS exposure. A delay period may be required to achieve optimal tungsten depositions following TMCTS use. Finally, the focusing conditions of the ion beam are found to have a significant impact on the resistance of FIB-deposited metal films. This effect is attributed to partial milling of the deposition film due to the intense current density of the collimated ion beam. The resistances of metal depositions performed with intentionally defocused ion beams were found to be lower than those performed with focused beams.

A method to improve the quality of 2.5 dimensional micro-and nano-structures produced by focused ion beam machining

Micron ◽  
2017 ◽  
Vol 101 ◽  
pp. 8-15 ◽  
Author(s):  
Daniele De Felicis ◽  
Muhammad Zeeshan Mughal ◽  
Edoardo Bemporad
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Nano Structures

TRANSPORT CHARACTERISTICS IN c-AXIS La2-xSrxCuO4 (LSCO) SINGLE CRYSTALS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 447-450
Author(s):  
SANG-JAE KIM ◽  
TAKESHI HATANO
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Critical Current ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Etching Method ◽  
First Time ◽  
Small Voltage

c-axis micro-bridges of La 2-x Sr x CuO 4 ( LSCO ) single crystals were fabricated by the focused-ion-beam (FIB) etching method. Small rectangular LSCO pieces were fabricated by cutting and grinding single crystals of underdoped LSCO of x=0.09. The size of LSCO single crystals between electrodes was cut to 20×40μm2 in ab-plane by using the FIB etching method. Superconductor-insulator-superconductor (SIS) like-branch structures on I-V curves of the LSCO stacks were observed for the first time. The branch structures exhibited voltage jumps of several tens mV in the range of from 1.7 K to 5 K with temperature dependence. When the temperature is changed from 5 K to 1.7 K , the critical current and the next branch split into a few of small voltage jumps with the intervals of several mV in the range of from 0.1 mV and 2.0 mV .

scholarly journals Automated cryo-lamella preparation for high-throughput in-situ structural biology

2019 ◽  
Author(s):  
Genevieve Buckley ◽  
Gediminas Gervinskas ◽  
Cyntia Taveneau ◽  
Hari Venugopal ◽  
James C. Whisstock ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Structural Biology ◽  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
Automated Method ◽  
Cellular Environment ◽  
Transmission Electron

AbstractCryo-transmission electron tomography (cryo-ET) in association with cryo-focused ion beam (cryo-FIB) milling enables structural biology studies to be performed directly within the cellular environment. Cryo-preserved cells are milled and a lamella with a thickness of 200-300 nm provides an electron transparent window suitable for cryo-ET imaging. Cryo-FIB milling is an effective method, but it is a tedious and time-consuming process, which typically results in ~10 lamellae per day. Here, we introduce an automated method to reproducibly prepare cryo-lamellae on a grid and reduce the amount of human supervision. We tested the routine on cryo-preserved Saccharomyces cerevisiae and demonstrate that this method allows an increased throughput, achieving a rate of 5 lamellae/hour without the need to supervise the FIB milling. We demonstrate that the quality of the lamellae is consistent throughout the preparation and their compatibility with cryo-ET analyses.

scholarly journals 50 nm Scale Alignment Method for Hybrid Manufacturing Processes for Full 3D Structuring

2020 ◽  
Vol 21 (12) ◽  
pp. 2407-2417
Author(s):  
Ki-Hwan Jang ◽  
Hae-Sung Yoon ◽  
Hyun-Taek Lee ◽  
Eunseob Kim ◽  
Sung-Hoon Ahn
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Research Area ◽  
Manufacturing Processes ◽  
Alignment Error ◽  
Alignment Method ◽  
Major Research ◽  
Hybrid Processes

AbstractIn micro-/nano-scale, multi-material three-dimensional (3D), structuring has been a major research area for making various applications. To overcome dimensional and material limitations, several hybrid processes have been proposed. The hybrid processes were performed in the same or different numerically controlled stages. If the stages differed, the substrate was moved and locked to the stage before fabrication. During the locking, alignment error occurred. This error became problematic because this significantly compromised the quality of final structures. Here, an alignment method for a hybrid process consisted of a focused ion beam milling, aerodynamically focused nanoparticle printing, and micro-machining was developed. Two sets of collinear marks were placed at the edges of the substrate. Rotational and translational errors were calculated and compensated using the marks. Processes having different scales were bridged through this alignment method. Various materials were utilized, and accuracy was less than 50 nm when the length of the substrate was less than 13 mm. The alignment method was employed to fabricate a V-shaped structure and step-shaped structure using polymer, ceramic, and metal.

scholarly journals Focused Ion Beam Milling of Single-Crystal Sapphire with A-, C-, and M-Orientations

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2871
Author(s):  
Qiuling Wen ◽  
Xinyu Wei ◽  
Feng Jiang ◽  
Jing Lu ◽  
Xipeng Xu
Keyword(s):  
Single Crystal ◽  
Surface Quality ◽  
Material Removal ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Crystal Orientations ◽  
Aluminum Ions ◽  
Single Crystal Sapphire

Sapphire substrates with different crystal orientations are widely used in optoelectronic applications. In this work, focused ion beam (FIB) milling of single-crystal sapphire with A-, C-, and M-orientations was performed. The material removal rate (MRR) and surface roughness (Sa) of sapphire with the three crystal orientations after FIB etching were derived. The experimental results show that: The MRR of A-plane sapphire is slightly higher than that of C-plane and M-plane sapphires; the Sa of A-plane sapphire after FIB treatment is the smallest among the three different crystal orientations. These results imply that A-plane sapphire allows easier material removal during FIB milling compared with C-plane and M-plane sapphires. Moreover, the surface quality of A-plane sapphire after FIB milling is better than that of C-plane and M-plane sapphires. The theoretical calculation results show that the removal energy of aluminum ions and oxygen ions per square nanometer on the outermost surface of A-plane sapphire is the smallest. This also implies that material is more easily removed from the surface of A-plane sapphire than the surface of C-plane and M-plane sapphires by FIB milling. In addition, it is also found that higher MRR leads to lower Sa and better surface quality of sapphire for FIB etching.

scholarly journals 4-Point Resistance Measurements of Individual Bi Nanowires

2001 ◽  
Vol 635 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu-Ming Lin ◽  
Pratibha L. Gai ◽  
Oded Rabin ◽  
Marcie R. Black ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
The Reformation ◽  
Bismuth Nanowires ◽  
Thick Oxide Layer ◽  
Bi Nanowire ◽  
Oxide Removal ◽  
Anodic Alumina Templates ◽  
Alternate Solution ◽  
Very High

AbstractWe have synthesized single crystal bismuth nanowires by pressure injecting molten Bi into anodic alumina templates. By varying the template fabrication conditions, nanowires with diameters ranging from 10 to 200nm and lengths of ~50[.proportional]m can be produced. We present a scheme for measuring the resistance of a single Bi nanowire using a 4-point measurement technique. The nanowires are found to have a 7nm thick oxide layer which causes very high contact resistance when electrodes are patterned on top of the nanowires. The oxide is found to be resilient to acid etching, but can be successfully reduced in high temperature hydrogen and ammonia environments. The reformation time of the oxide in air is found to be less than 1 minute. Focused ion beam milling is attempted as an alternate solution to oxide removal.

Influence of Domain Structure on Magnetoresistance in Perovskite Manganite Grain Boundary Junctions

2001 ◽  
Vol 674 ◽  
Author(s):  
Robert Gunnarsson ◽  
Anatoli Kadigrobov ◽  
Zdravko Ivanov
Keyword(s):  
Grain Boundary ◽  
Temperature Dependence ◽  
Focused Ion Beam ◽  
Domain Walls ◽  
Ion Beam ◽  
Perovskite Manganite ◽  
Current Voltage ◽  
Single Grain ◽  
Current Voltage Characteristics ◽  
The Impact

ABSTRACTWe have been able to deduce a temperature dependence of the built-in potential in La2/3Sr1/3MnO3 grain boundary junctions. This has been performed by trimming a single grain boundary down to 1μm width with a focused ion-beam. We can thereby see the impact of single domain walls on the magnetoresistance and the current-voltage characteristics. We have also demonstrated the effect of averaging as we increased the number of junctions.

scholarly journals Collection of continuous rotation MicroED Data from Ion Beam Milled Crystals of Any Size

2018 ◽  
Author(s):  
Michael W. Martynowycz ◽  
Wei Zhao ◽  
Johan Hattne ◽  
Grant J. Jensen ◽  
Tamir Gonen
Keyword(s):  
Data Collection ◽  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Air Interface ◽  
Structure Solution ◽  
Continuous Rotation ◽  
Macromolecular Protein ◽  
Subsequent Sample

AbstractMicrocrystal electron diffraction (MicroED) allows for macromolecular structure solution from nanocrystals. To create crystals of suitable size for MicroED data collection, sample preparation typically involves sonication or pipetting a slurry of crystals from a crystallization drop. The resultant crystal fragments are fragile and the quality of the data that can be obtained from them is sensitive to subsequent sample preparation for cryoEM as interactions in the water-air interface can damage crystals during blotting. Here, we demonstrate the use of a focused ion beam to generate lamellae of macromolecular protein crystals for continuous rotation MicroED that are of ideal thickness, easy to locate, and require no blotting optimization. In this manner, crystals of nearly any size may be scooped and milled to ideal dimensions prior to data collection, thus streamlining the methodology for sample preparation for MicroED.

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