scholarly journals Cobalt Content Effect on the Magnetic Properties of Ni50-xCoxMn35.5In14.5 Annealed Ribbons

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5497
Author(s):  
Łukasz Dubiel ◽  
Andrzej Wal ◽  
Ireneusz Stefaniuk ◽  
Antoni Żywczak ◽  
Piotr Potera ◽  
...  

We present a study of the annealing effect and its influence on magnetic and structural properties for a series of Heusler alloys Ni50−xCoxMn35.5In14.5 (x=0,3,5) prepared in ribbon form. We studied the morphology and composition using scanning electron microscopy (SEM) equipped with an X-ray microanalyzer (EDX). The magnetic properties were determined by two methods: electron magnetic resonance (EMR) and vibrating sample magetometer (VSM). We found that cobalt content in the annealed samples reveals an additional magnetic phase transition at lower temperatures.

2017 ◽  
Vol 371 ◽  
pp. 44-48
Author(s):  
Young Min Kim ◽  
Min Jung Kang

In this study, we analyzed weld cracking in Ni-based superalloys. Alloys with about 64 wt.% Ni and 31 wt.% Ni were used for the weld metal analysis. Phase transition predicted by thermodynamic calculation were compared with experimental results. The weld metal’s microstructure was analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) mapping, and its mechanical properties tested. From EDX mapping, it was established that the alloying elements (Nb and Mo) were segregated around the weld crack as a result of the formation of a niobium carbide (NbC).


2010 ◽  
Vol 8 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Junhao Zhang ◽  
Ling Yang ◽  
Xiaofang Cheng ◽  
Jinmeng Zhang ◽  
Fucai Li

AbstractHierarchical nickel microwires with nanothorns were fabricated through a reduction of nickelous salt with hydrazine in diethanolamine. The product was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The growth mechanism of the nickel microwires with nanothorns is proposed, based on the evolution of the structures and morphologies, which could be ascribed to the cooperative effect of the complexant of diethanolamine and inherent magnetic interactions. Magnetic properties of the product were measured at room temperature and compared with other shaped counterparts.


2007 ◽  
Vol 561-565 ◽  
pp. 1141-1144
Author(s):  
Xiao Bai Chen ◽  
Hong Qiu ◽  
Ping Wu ◽  
Yue Tian

180nm-thick Ni33Fe67 and Ni21Fe79 films were deposited on SiO2/Si(100) substrates at 633 K by DC magnetron co-sputtering. Structural, electrical and magnetic properties of the films were investigated using X-ray diffraction, field emission scanning electron microscopy, a four-point probe technique and an alternating gradient magnetometer. The Ni21Fe79 film has a single bcc structure whereas the Ni33Fe67 film is a fcc-bcc mixed phase. The films grow with granular grains. The grain shape of the Ni21Fe79 film is triangular and rectangular. The Ni33Fe67 film consists of irregular shaped grains and a few large triangular grains. The grain size of the Ni21Fe79 film is larger than that of the Ni33Fe67 film. The resistivities of the Ni21Fe79 and Ni33Fe67 films are 1.82×10-63m and 1.09×10-63m. The saturation magnetization of the Ni21Fe79 and Ni33Fe67 films are 1.09×106 A/m and 1.02×106 A/m. The coercivity of the Ni21Fe79 and Ni33Fe67 films are 2.06×104 A/m and 8.84×103 A/m , respectively.


2010 ◽  
Vol 660-661 ◽  
pp. 308-313
Author(s):  
S.C. Silva ◽  
José Hélio Duvaizem ◽  
Rubens Nunes de Faria Jr. ◽  
Hidetoshi Takiishi

The first goal of this work involved the study of HDDR powders obtained from annealed alloys with the general formula: PrxFe77.9-xCo16B6Nb0.1 (x = 12; 12.5; 13; 13.5 and 14). The alloys were processed at desorption / recombination temperature of 840°C. The highest magnetic properties were obtained with 13.5 at. % Pr (Br= 1000mT and µ0iHc= 890mT). The alloy with a minimum praseodymium content (12 at. %) exhibited the lowest magnetic properties (Br= 350mT e iHc= 120mT). The second aim of the work involved the characterization of HDDR powders using X-ray diffraction for phase quantification and mean crystallite sizes determination of the hard magnetic phase. The processed powders were characterized by scanning electron microscopy (SEM).


2010 ◽  
Vol 660-661 ◽  
pp. 302-307
Author(s):  
P.B. Santos ◽  
S.C. Silva ◽  
Rubens Nunes de Faria Jr. ◽  
Hidetoshi Takiishi

The first goal of this work involved the study of the effect of variables the HDDR processing, such as: the added pressure of H2 in the system, the time of heat treatment and recombination of Pr12Fe65.9Co16B6Nb0.1 alloy with the aim of improving the magnetic properties like the magnetic properties of the Pr14Fe63.9Co16B6Nb0.1 alloy (Br= 865mT and iHc= 790mT). The second aim of the work involved the characterization of HDDR powders that were analyzed by X-ray diffraction for identification and quantification of crystalline phases. These materials were analyzed by scanning electron microscopy (SEM).


2017 ◽  
Vol 891 ◽  
pp. 478-482
Author(s):  
Erika Mudra ◽  
Magdalena Streckova ◽  
Alexandra Kovalcikova ◽  
Martin Šebek ◽  
Vladimír Girman ◽  
...  

In this study the needle-less electrospinning by means of “NanospiderTM“ (ELMARCO) as technology for the preparation of fine α-Al2O3 fibers with diameters of 0.5 - 1.5 µm is presented. The fabrication consists of three steps: i) preparation of spinning solution, ii) electrospinning of the prepared solution and collection of the composite fibers, iii) calcination of the composite precursor fibers. The electrospun fibers were prepared from polyacrylonitrile/N,N-dimethylformamide (PAN/DMF) polymer solution and Al(NO3)3.9H2O in ratio 1/10/1. Thereafter, the precursor fibers were calcined in the furnace at 900, 1100 and 1200 °C with a rate of 5 °C/min in air. The formation of crystalline phases, surface morphology and diameters of metastable and final alumina fibers were characterized using thermogravimetric analysis, X-ray diffraction analysis, the scanning electron microscopy and transmission electron microscopy. The precursor PAN/Al(NO3)3 fibers were amorphous. The thermal treatment leads to the phase transition from γ-Al2O3 to α-Al2O3 accompanied by removing of polyacrylonitrile (PAN). The fine porous microfibers composed of pure α-Al2O3 phase were prepared after calcinations at 1200 °C.


2018 ◽  
Vol 36 (2) ◽  
pp. 310-319 ◽  
Author(s):  
Gnana Praveena Nethala ◽  
Ravindar Tadi ◽  
Aroli Venkateswara Anupama ◽  
Satish Laxman Shinde ◽  
V. Veeraiah

Abstract Mg substituted cobalt ferrite spinel powder samples with the general formula MgxCO1-xFe2O4(x = 0 to 0.25) were synthesized chemically through sol-gel method and annealed at 1100 °C for 2 h. They were initially screened for the structural and morphological properties by X-ray diffraction and field emission scanning electron microscopy, respectively. Vibrational properties of the samples were studied by Raman and infrared spectroscopies. X-ray diffraction confirmed the formation of single pure or near-pure phase with cubic spinel structure for all the samples with expected occupancy values. The field emission scanning electron microscopy revealed a decrease in the particle size with an increase in Mg concentration. Both structural and magnetic properties of the samples were characterized using Mössbauer spectroscopy while the magnetic properties were studied using vibrating sample magnetometry. The changes in magnetic moment of ions, their coupling with neighboring ions and cation exchange interactions were confirmed from the Mössbauer spectroscopy analysis. Saturation magnetization and coercivity values can be explained based on the Slater-Pauling curve. The magnetometry results showed a decrease in saturation magnetization of the samples with increase in Mg concentration


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.


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