Electrochemical etching down to one-monolayer towards high-Tc superconductivity
Figure: Schematic of electric-double-layer transistor device and electrochemical reaction on FeSe surface. (Left) Device structure of electric-double-layer transistor with FeSe channel deposited on oxide substrate. (Right) One-monolayer FeSe is realized by electrochemical etching where Fe and Se ions are dissolved into ionic liquid. Copyright : Tohoku University
Iron selenide (FeSe) is an attracting superconducting material since the superconducting transition temperature (Tc) is enhanced from 8 K in bulk form toward 65 K in one-monolayer form.
However, systematic thickness dependence of electrical measurement has been difficult to address.
A team of researchers at Tohoku University's Institute for Materials Research (IMR), has realized layer-by-layer etching in superconducting FeSe films down to approximately one-monolayer about 0.6 nm using classical electrochemical reaction in electric-double-layer transistor configuration.
As the thickness of the films becomes thin, the superconducting transition temperature (Tc) is increased from bulk value (8 K) to about 40 K.
In addition, the research group unveils that by combining with an electrostatic charging effect, the high-Tc transition can be induced in 10-nm thick condition (20 monolayers), which had been limited in one/two-monolayers so far.
The development of this etching technique will pave the way for the exploration of nontrivial physical phenomena in atomically thin two-dimensional films. This had previously been difficult to address by conventional methods.
This work was published in Nature Physics online on Nov 2, 2015.
Publication Information
Authors: J. Shiogai, Y. Ito, T. Mitsuhashi, T. Nojima and A. Tsukazaki
Title: Electric-field-induced superconductivity in electrochemically etched ultrathin FeSe films on SrTiO3 and MgO
Journal: Nature Physics
DOI: 10.1038/nphys3530
Contact:
Junichi Shiogai
Institute of Materials Research, Tohoku University
Email: junichi.shiogaiimr.tohoku.ac.jp
Atsushi Tsukazaki
Institute of Materials Research, Tohoku University
Email: tsukazakiimr.tohoku.ac.jp
Associated links
Original article from Tohoku Unviersity
Media Contact
More Information:
http://www.researchsea.comAll latest news from the category: Materials Sciences
Materials management deals with the research, development, manufacturing and processing of raw and industrial materials. Key aspects here are biological and medical issues, which play an increasingly important role in this field.
innovations-report offers in-depth articles related to the development and application of materials and the structure and properties of new materials.
Newest articles
Thermodynamics-Inspired Laser Beam Shaping Sparks a Ray of Hope
Inspired by ideas from thermodynamics, researchers at the University of Rostock and the University of Southern California have developed a new method to efficiently shape and combine high-energy laser beams….
A Breath of Fresh Air: Advanced Quantum Calculations Enable COF-999 CO₂ Adsorption
Quantum chemical calculations at HU enable the development of new porous materials that are characterized by a high absorption capacity for CO2 Climate experts agree: To overcome the climate crisis,…
Why Global Droughts Tied to Climate Change Have Left Us Feeling Under the Weather
A study led by the Swiss Federal Institute for Forest, Snow and Landscape Research WSL shows that there has been a worrying increase in the number of long droughts over…