Structural and magnetic properties of hard magnetic system Ce(Co1-xFex)4.4Cu0.6 (0 ≤ x ≤ 0.19)

Thumbnail Image
Date
2021-06-19
Authors
Palasyuk, Olena
Onyszczak, Michael
Kim, Tae-Hoon
Zhou, Lin
Kramer, Matthew
Bud’ko, Sergey
Canfield, Paul
Palasyuk, Andriy
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Canfield, Paul
Distinguished Professor
Research Projects
Organizational Units
Organizational Unit
Organizational Unit
Physics and Astronomy
Physics and astronomy are basic natural sciences which attempt to describe and provide an understanding of both our world and our universe. Physics serves as the underpinning of many different disciplines including the other natural sciences and technological areas.
Organizational Unit
Materials Science and Engineering
Materials engineers create new materials and improve existing materials. Everything is limited by the materials that are used to produce it. Materials engineers understand the relationship between the properties of a material and its internal structure — from the macro level down to the atomic level. The better the materials, the better the end result — it’s as simple as that.
Journal Issue
Is Version Of
Versions
Series
Department
Ames National LaboratoryPhysics and AstronomyMaterials Science and Engineering
Abstract

The Ce(Co1-xFex)4.4Cu0.6 (0 ≤ x ≤ 0.19) is a composite, hard magnetic system that is based on the CaCu5-type structure (1:5). It shows both, unique magnetic and microstructural features that are essential for permanent magnets, e.g., exceptional squareness of the 2nd. quadrant of the magnetization loops and microstructural features typically needed for pinning. Samples solidified in alumina crucibles are coarse-grained and often clearly faceted and readily align in a magnetic field. X-ray, SEM, and TEM analyses show a 1:5-type single-phase material when quenched from high temperature, which, after heat treatment, transforms into a laminar coherent nanostructure through the formation of a dense array of extended intercalated regions. These extended intercalated regions are comprised of segments of the Ce2Ni7–type structure (2:7) which segregate into various closely related precipitates forming a nanostructure similar to the SmCo5 - Sm2Co17 composites seen in Sm-Co permanent magnets. Based on TEM and Lorentz microscopy of well-aligned single grain particles, the magnetic domains’ reversal mechanism is regulated by anisotropy fluctuations occurring along the easy direction of magnetization and strong exchange interactions between the matrix and defects (e.g.: stacking faults). Lorentz microscopy suggests the domain wall is not physically pinned by the defect, but rather is offset/deflected when it interacts with the defect. The Lorentz and magnetization data suggest that defects cause a bending of the moment away from the c axis inside the grains.

Comments
Description
Keywords
Citation
DOI
Subject Categories
Copyright
Collections