Magnetic property enhancement of cobalt-free M-type strontium hexagonal ferrites by CaCO3 and SiO2 addition

Ching Chien Huang; Ai Hua Jiang; Ching Hsuan Liou; Yi Chen Wang; Chi Ping Lee; Tong Yin Hung; Chun Chung Shaw; Yung Hsiung Hung; Ming Feng Kuo; Chun Hu Cheng

doi:10.1016/j.intermet.2017.06.001

Magnetic property enhancement of cobalt-free M-type strontium hexagonal ferrites by CaCO₃ and SiO₂ addition

Ching Chien Huang^*, Ai Hua Jiang, Ching Hsuan Liou, Yi Chen Wang, Chi Ping Lee, Tong Yin Hung, Chun Chung Shaw, Yung Hsiung Hung, Ming Feng Kuo, Chun Hu Cheng

^*Corresponding author for this work

Department of Mechatronic Engineering

Research output: Contribution to journal › Article › peer-review

22 Citations (Scopus)

Abstract

An experiment was performed to investigate whether CaCO₃ and SiO₂ addition enhances the magnetic properties of cobalt-free M-type Sr ferrites, in which experimental parameters such as additive composition and the CaCO₃/SiO₂ ratio were changed. The specimens were prepared using conventional ceramic techniques. CaCO₃ addition promoted densification and uniform grain growth, resulting in high remanence; however, with the simultaneous addition of CaCO₃ and SiO₂, coercivity decreased to 3046 Oe in Sr ferrite hard magnets without Co₃O₄. SiO₂ addition suppressed grain growth. The addition of appropriate concentrations of CaCO₃ and SiO₂ as additives after calcination was shown to be very beneficial for tailoring a dense microstructure with relatively small grains. A CaCO₃/SiO₂ ratio of approximately 1.8 was found to be optimum, and the magnetic properties of B_r = 4.3 kG, iH_c = 3.7 kOe, and (BH)_max = 4.5 MGOe were obtained for Sr ferrite hard magnets without Co₃O₄, which are acceptable for motor applications under output power <1 kW.

Original language	English
Pages (from-to)	111-117
Number of pages	7
Journal	Intermetallics
Volume	89
DOIs	https://doi.org/10.1016/j.intermet.2017.06.001
Publication status	Published - 2017 Oct

Keywords

Additives
Cobalt
Hard magnet
M-type
Sr ferrites

ASJC Scopus subject areas

General Chemistry
Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.intermet.2017.06.001

Cite this

@article{fcc0239f51de4af2848095da2e4b9b50,

title = "Magnetic property enhancement of cobalt-free M-type strontium hexagonal ferrites by CaCO3 and SiO2 addition",

abstract = "An experiment was performed to investigate whether CaCO3 and SiO2 addition enhances the magnetic properties of cobalt-free M-type Sr ferrites, in which experimental parameters such as additive composition and the CaCO3/SiO2 ratio were changed. The specimens were prepared using conventional ceramic techniques. CaCO3 addition promoted densification and uniform grain growth, resulting in high remanence; however, with the simultaneous addition of CaCO3 and SiO2, coercivity decreased to 3046 Oe in Sr ferrite hard magnets without Co3O4. SiO2 addition suppressed grain growth. The addition of appropriate concentrations of CaCO3 and SiO2 as additives after calcination was shown to be very beneficial for tailoring a dense microstructure with relatively small grains. A CaCO3/SiO2 ratio of approximately 1.8 was found to be optimum, and the magnetic properties of Br = 4.3 kG, iHc = 3.7 kOe, and (BH)max = 4.5 MGOe were obtained for Sr ferrite hard magnets without Co3O4, which are acceptable for motor applications under output power <1 kW.",

keywords = "Additives, Cobalt, Hard magnet, M-type, Sr ferrites",

author = "Huang, {Ching Chien} and Jiang, {Ai Hua} and Liou, {Ching Hsuan} and Wang, {Yi Chen} and Lee, {Chi Ping} and Hung, {Tong Yin} and Shaw, {Chun Chung} and Hung, {Yung Hsiung} and Kuo, {Ming Feng} and Cheng, {Chun Hu}",

note = "Publisher Copyright: {\textcopyright} 2017 Elsevier Ltd",

year = "2017",

month = oct,

doi = "10.1016/j.intermet.2017.06.001",

language = "English",

volume = "89",

pages = "111--117",

journal = "Intermetallics",

issn = "0966-9795",

publisher = "Elsevier Limited",

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T1 - Magnetic property enhancement of cobalt-free M-type strontium hexagonal ferrites by CaCO3 and SiO2 addition

AU - Huang, Ching Chien

AU - Jiang, Ai Hua

AU - Liou, Ching Hsuan

AU - Wang, Yi Chen

AU - Lee, Chi Ping

AU - Hung, Tong Yin

AU - Shaw, Chun Chung

AU - Hung, Yung Hsiung

AU - Kuo, Ming Feng

AU - Cheng, Chun Hu

PY - 2017/10

Y1 - 2017/10

N2 - An experiment was performed to investigate whether CaCO3 and SiO2 addition enhances the magnetic properties of cobalt-free M-type Sr ferrites, in which experimental parameters such as additive composition and the CaCO3/SiO2 ratio were changed. The specimens were prepared using conventional ceramic techniques. CaCO3 addition promoted densification and uniform grain growth, resulting in high remanence; however, with the simultaneous addition of CaCO3 and SiO2, coercivity decreased to 3046 Oe in Sr ferrite hard magnets without Co3O4. SiO2 addition suppressed grain growth. The addition of appropriate concentrations of CaCO3 and SiO2 as additives after calcination was shown to be very beneficial for tailoring a dense microstructure with relatively small grains. A CaCO3/SiO2 ratio of approximately 1.8 was found to be optimum, and the magnetic properties of Br = 4.3 kG, iHc = 3.7 kOe, and (BH)max = 4.5 MGOe were obtained for Sr ferrite hard magnets without Co3O4, which are acceptable for motor applications under output power <1 kW.

AB - An experiment was performed to investigate whether CaCO3 and SiO2 addition enhances the magnetic properties of cobalt-free M-type Sr ferrites, in which experimental parameters such as additive composition and the CaCO3/SiO2 ratio were changed. The specimens were prepared using conventional ceramic techniques. CaCO3 addition promoted densification and uniform grain growth, resulting in high remanence; however, with the simultaneous addition of CaCO3 and SiO2, coercivity decreased to 3046 Oe in Sr ferrite hard magnets without Co3O4. SiO2 addition suppressed grain growth. The addition of appropriate concentrations of CaCO3 and SiO2 as additives after calcination was shown to be very beneficial for tailoring a dense microstructure with relatively small grains. A CaCO3/SiO2 ratio of approximately 1.8 was found to be optimum, and the magnetic properties of Br = 4.3 kG, iHc = 3.7 kOe, and (BH)max = 4.5 MGOe were obtained for Sr ferrite hard magnets without Co3O4, which are acceptable for motor applications under output power <1 kW.

KW - Additives

KW - Cobalt

KW - Hard magnet

KW - M-type

KW - Sr ferrites

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