Phase transition of chemically synthesized FePt nanoparticles under high pressure

Date

2018-01-01

Author

ŞİMŞEK, TELEM
Karci, Ozgur
ÖZCAN, ŞADAN

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

175
views

0
downloads

We present the results of a study related to phase transformation of chemically synthesized FePt nanoparticles under high pressure from face-centered cubic into face-centered tetragonal structure. As-synthesized nanoparticles are around 4.5 nm and show superparamagnetic behavior at 300 K. After annealing under 60 bar pressure of hydrogen at 400 degrees C for 2 h, nanoparticles exhibit strong ferromagnetic behavior with 5391 Oe coercivity. Results show that high-pressure annealing lowers the decomposition temperature of the surfactants surrounding nanoparticles and partially hinders agglomeration arising from heat treatment. The promising ferromagnetic properties of the FePt nanoparticles after annealing under high pressure make them suitable for ultrahigh-density memory devices.

Subject Keywords

General Chemistry

URI

https://hdl.handle.net/11511/67213

Journal

TURKISH JOURNAL OF CHEMISTRY

DOI

https://doi.org/10.3906/kim-1711-57

Collections

Unclassified, Article

Suggestions

OpenMETU
Core

Germanium determination by flame atomic absorption spectrometry: An increased vapor pressure-chloride generation system Kaya, Murat; Volkan, Mürvet (Elsevier BV, 2011-03-15) A new chloride generation system was designed for the direct, sensitive, rapid and accurate determination of the total germanium in complex matrices. It was aimed to improve the detection limit of chloride generation technique by increasing the vapor pressure of germanium tetrachloride (GeCl4). In order to do so, a novel joint vapor production and gas-liquid separation unit equipped with a home-made oven was incorporated to an ordinary nitrous oxide-acetylene flame atomic absorption spectrometer. Several va...
Experimental investigation of drag reduction effects of polymer additives on turbulent pipe flow using ultrasound Doppler velocimetry Zeybek Vural, Serife; Bayram, Göknur; Uludağ, Yusuf (The Scientific and Technological Research Council of Turkey, 2014-01-01) Drag reduction in fully developed turbulent pipe flow with 4 concentrations (200 to 500 wppm or mg/kg) of low molecular weight sodium carboxymethylcellulose (CMC) in aqueous solutions was investigated experimentally. Drag reduction was determined by pressure drop measurements. Maximum drag reduction achieved was 22% using 500 wppm CMC solution. To observe the impact of the presence of CMC on the flow, ultrasound Doppler velocimetry (UDV) was employed to monitor the instantaneous velocity distributions. Expe...
CATALYTIC CHARACTERISTICS OF MASSIVE AND LOADED SULFONIC RESINS IN THE SYNTHESIS OF ETHYL tert-BUTYL ETHER AT ATMOSPHERIC AND INCREASED PRESSURE Vlasenko, N. V.; Kochkin, Yu. N.; Strizhak, P. E.; Doğu, Timur; DOĞU, GÜLŞEN; OKTAR, NURAY; Degirmenci, L. (Springer Science and Business Media LLC, 2010-11-01) The catalytic characteristics of massive and loaded sulfonic resins in the synthesis of ethyl tert-butyl ether at atmospheric and increased pressures have been compared. It has been established that massive sulfonic resins are more active than loaded resins at atmospheric pressure. At higher pressures, on the other hand, the activity and selectivity of catalysts are greater the lower the content of polymer as a result of the increased effectiveness of the acid centers.
Aryl butenoic acid derivatives as a new class of histone deacetylase inhibitors: synthesis, in vitro evaluation, and molecular docking studies Esiyok, Peruze Ayhan; Seven, Ozlem; Eymur, Guluzar; Tatar, Gamze Bora; DAYANGAÇ ERDEN, DİDEM; YELEKÇİ, Kemal; YURTER, HAYAT; Demir, Ayhan Sıtkı (The Scientific and Technological Research Council of Turkey, 2014-01-01) New aryl butenoic acid derivatives have been synthesized by combining hydroxy- or methoxy-substituted phenyl rings as the capping group, with a double bond in the short linker as well as metal binding groups, enoic ester, and salts bearing either methyl or morpholine. These compounds have been shown to possess promising histone deacetylase inhibition activities via in vitro fluorometric assay and molecular docking studies.
ANODIC POTENTIAL HOMO ENERGY RELATIONS OF FLUORENE DERIVATIVES SEN, S; CELEBI, N; TURKER, L; Önal, Ahmet Muhtar (Wiley, 1993-09-01) Anodic oxidation peak potentials (E(p,a)) of some fluorene derivatives were measured on a Pt-degrees electrode versus Ag-degrees/Ag+ in acetonitrile-TBAFB by cyclic voltammetry. The highest occupied molecular orbital (HOMO) energies of the compounds were calculated within the Huckel molecular orbital (HMO) framework. The measured E(p,a) values were correlated to theoretical HOMO energies with a linear regression model.

Citation Formats

T. ŞİMŞEK, O. Karci, and Ş. ÖZCAN, “Phase transition of chemically synthesized FePt nanoparticles under high pressure,” TURKISH JOURNAL OF CHEMISTRY, pp. 1217–1223, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/67213.