We report here on a simple but precise thermoelectric power measurement setup that can be adapted for different environments. This setup has been extensively used for cryogen-free environment to measure a variety of samples. It is made simple to load and hold the sample between two copper blocks by a spring-shaft arrangement. The usable range of measurements is a few microV/K to a few hundreds of microV/K. The salient features of the setup in achieving good precision both in natural warm-up/cooldown and controlled measurements are (i) the continuous DeltaT control across the sample by a chromel-AuFe(0.07%) thermocouple and (ii) the measurements of emf generated across the sample and the thermocouple using a nanovoltmeter and a scanner system. The versatile nature of the setup is further demonstrated by employing it in a magnetic field environment up to 140 kOe. The precision achieved using this system is highlighted for a few systems of current interest.

Simple and precise thermoelectric power measurement setup for different environments

By means of magnetization, specific heat, and muon-spin relaxation measurements, we investigate newly synthesized high-pressure oxidized Cu0.75Mo0.25Sr2YCu2O7.54, in which overdoping is achieved up to p∼0.46 hole/Cu, well beyond the Tc−p superconducting dome of cuprates, where Fermi-liquid behavior is expected. Surprisingly, we find bulk superconductivity with Tc=84 K and superfluid density similar to those of optimally doped YBa2Cu3O7−δ. On the other hand, specific heat data display a large electronic contribution at low temperature, comparable to that of nonsuperconducting overdoped La2−xSrxCuO4. These results point at an unusual high-Tc phase with a large fraction of unpaired holes. Further experiments may assess the Fermi-liquid properties of the present phase, which would put into question the paradigm that the high Tc of cuprates originates from a non-Fermi-liquid ground state.

https://research.aalto.fi/files/10241531/PhysRevB.94.pdf

Bulk superconductivity at 84 K in the strongly overdoped regime of cuprates

Systematic CuL2,3-edge and OK-edge XANES spectroscopy study on the infinite-layer superconductor system, (Sr,La)CuO2

Here we demonstrate that the Cu L-edge XANES (X-ray absorption near-edge structure) spectroscopy can be employed for quantitative analysis of the level of carrier-doping in the prototype hole- and electron-doped high-T c superconductor systems, (La 1-x sr x ) 2 CuO 4+δ and (Nd 1-x Ce x ) 2 CuO 4+δ . The progress in hole-doping in the (La 1-x Sr x ) 2 CuO 4+δ system is seen as development of the shoulder peak (due to nominally trivalent copper) on the high-energy side of the main peak (due to nominally divalent copper) in the Cu L 3 -edge region, whereas the progress in electron-doping in the (Nd 1-x Ce x ) 2 CuO 4+δ system results in an additional absorption peak at about 934 eV (due to nominally monovalent copper), together with a decrease in the intensity of the main peak (due to nominally divalent copper). On the basis of these features, Cu-valence values are quantitatively obtained in excellent agreement with those calculated for the same samples from the precise oxygen contents, 4+δ, determined by means of wet-chemical analysis. The valence of Ce in (Nd 1-x Ce x ) 2 CuO 4+δ is revealed to be somewhat lower than +4 (ca. +3.8) on the basis of Ce M 5 -edge XANES data. In the O K-edge XANES spectra, the increase in the CuO 2 -plane hole concentration with increasing x in (La 1-x Sr x ) 2 CuO 4+δ is seen as an enhancement in the intensity of the pre-edge feature at ∼528.9 eV, whereas for (Nd 1-x Ce x ) 2 CuO 4+δ , no signs are observed that could be directly assigned to the change in electron-doping level.

/pdf/quantitative-xanes-spectroscopy-study-on-the-prototype-hole-4qw14b4h7u.pdf

Quantitative XANES Spectroscopy Study on the Prototype Hole- and Electron-Doped High-Tc Superconductor Systems, (La,Sr)2CuO4 and (Nd,Ce)2CuO4

Homologous series of (Cu,Mo)Sr2(Y,Ce)sCu2O5+2s+δ copper-oxide superconductors: Synthesis of members up to s=6

Superconductivity in the `triple-fluorite-layer¿ copper oxides (Cu,M)-1232 (M=Mo, W, Re, Pb)

Series of samples of the composition Cu (Y1−xCax)Ba2Cu3O6+δ () have been prepared by a solid-state synthesis route. Precise oxygen content was determined for all the samples by iodometric titration. The c lattice parameter increases with increasing x, indicating successful substitution of Y3+ by the bigger Ca2+ ion. Resistivity (R) versus temperature (T) measurements show that the pristine sample (x = 0.0) is semiconducting down to 5 K. Induction of superconductivity is seen with increasing x. The x = 0.10 sample exhibits the onset of superconducting transition (Tconset) at 42 K without attaining a zero resistance superconducting transition temperature (TcR = 0) state above 5 K. For the x = 0.15 and 0.20 samples TcR = 0 is observed at 25 and 35 K with Tconset at 52 and 61 K, respectively. DC magnetic susceptibility measurements corroborated the findings from the resistivity measurements. Thermoelectric power (S) measurements in the temperature range of 5–300 K exhibit TcS = 0 at 25 and 35 K respectively for x = 0.15 and 0.20 samples. The room-temperature S value decreases with increasing x, indicating an enhanced number of mobile holes. Magneto-transport measurements in applied magnetic fields of 3 and 6 T show a broadening of the superconducting transition. These results will be useful in constructing a more complete phase diagram of the Cu (Y1−xCax)Ba2Cu3O6+δ system in terms of x and δ.

Systematic induction of superconductivity in the Cu (Y1−xCax)Ba2Cu2O6+δ (\delta \approx 0.3 ) system by Ca substitution

Oxygen nonstoichiometry and valence of copper in the Cu-1222 superconductor

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. Arai

Author Tools

Chat about Author

Papers

Superconductivity in the `triple-fluorite-layer¿ copper oxides (Cu,M)-1232 (M=Mo, W, Re, Pb)

Systematic induction of superconductivity in the Cu (Y1−xCax)Ba2Cu2O6+δ (\delta \approx 0.3 ) system by Ca substitution

Oxygen nonstoichiometry and valence of copper in the Cu-1222 superconductor