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| magnetic_saturation [2025/02/08 18:10] – [Typical saturation values] stan_zurek | magnetic_saturation [2025/02/15 15:38] (current) – [Saturation values: Hsat, Bsat, Msat, Jsat] stan_zurek |
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| | ===== Typical saturation values ===== |
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| | There are many magnetic materials ([[alloy|alloys]], [[ferrite|ferrites]], and [[composite|composites]]) widely used in industry, for which well-established values of magnetic saturation are known.[(Cullity)][(Fiorillo)] Significant research was carried out in the past in order to identify the material with the highest saturation magnetisation, and it was discovered that the Co-Fe alloys resulted with the highest values. However, cobalt is an expensive material, and thus it would be beneficial if alternative materials were identified. Recent research effort suggests that further optimisation can be achieved for new alloys, which push the boundaries to as high as 2.43 T.[(YahaoLi>[[https://doi.org/10.1016/j.scriptamat.2024.116485|Yahao Li, Errui Jiang, Kaijia Hu, Yongqian Peng, Ziqi Ni, Fengqi Liu, Yicong Ye, Shun Li, Shuxin Bai, Active learning-enabled the discovery of ultra-high saturation magnetization soft magnetic alloys, Scripta Materialia, |
| | Vol. 257, 2025, 116485, https://doi.org/10.1016/j.scriptamat.2024.116485]])] |
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| | ^ Typical saturation polarisation //J<sub>sat</sub>// values [(Fiorillo)][(Cullity)][(YahaoLi)] ^^ |
| | | Fe70-Co25-Ni4-Si1 | 2.43 T | |
| | | Co49-Fe49-V2 | 2.35 T | |
| | | Fe | 2.15 T | |
| | | Co | 2.15 T | |
| | | Ni50-Fe50 | 1.60 T | |
| | | Ni36-Fe64 | 1.30 T | |
| | | Ni80-Fe15-Mo5 | 0.80 T | |
| | | Ni77-Fe14-Cu5-Mo4 | 0.78 T | |
| | | Ni | 0.608 T | |
| | | FeFe<sub>2</sub>O<sub>4</sub> | 0.603 T | |
| | | CoFe<sub>2</sub>O<sub>4</sub> | 0.534 T | |
| | | MnFe<sub>2</sub>O<sub>4</sub> | 0.503 T | |
| | | NiFe<sub>2</sub>O<sub>4</sub> | 0.340 T | |
| | | MgFe<sub>2</sub>O<sub>4</sub> | 0.151 T | |
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| | Nevertheless, magnetic saturation is only one parameter important for design of [[electromagnetic device|electromagnetic devices]], and for optimum performance other values are also critical, such as [[power loss]], or [[magnetic permeability]]. |
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| * [[magnetic field strength]] **//H//** - Theoretically, magnetic excitation can be always increased with increasing amount of applied electric current, therefore there is no limited value of "//H<sub>sat</sub>//" arising from the magnetic properties of the magnetised material. There is a practical limitation to the amount of current which can be sustained in a conductor due to thermal and/or superconducting [[critical field]] limits, but these are not related to the magnetic saturation as understood from the viewpoint of aligning magnetic dipole moments. | * [[magnetic field strength]] **//H//** - Theoretically, magnetic excitation can be always increased with increasing amount of applied electric current, therefore there is no limited value of "//H<sub>sat</sub>//" arising from the magnetic properties of the magnetised material. There is a practical limitation to the amount of current which can be sustained in a conductor due to thermal and/or superconducting [[critical field]] limits, but these are not related to the magnetic saturation as understood from the viewpoint of aligning magnetic dipole moments. |
| * [[magnetic flux density]] **//B//** - If //H// is present, then the $μ_0·H$ component is always present, and therefore increasing the excitation in a form of //H// will always produce an increase in the corresponding magnetic flux density //B// (when discussing amplitudes near saturation). Hence, it is also not possible to achieve some limiting value of "//B<sub>sat</sub>//" (and consequently there is no "saturation flux density" nor "saturation induction"). However, in practical cases it is sometimes useful to refer to the state of a material which is near saturation with some specific value of "//B<sub>sat</sub>//". Nevertheless, there is an implicit assumption that only some "technical saturation" is attained rather than full saturation. For example, in analysis of hysteresis loops of permanent magnets the "//B<sub>sat</sub>//" (or "//B<sub>s</sub>//") point could mean a state when just //J<sub>sat</sub>// was reached, even though //B// would continue to increase linearly beyond that point.[(Arnold>[[https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Vocabulary-of-Magnetism.pdf|Arnold Magnetic Technologies, TECHNotes, The Vocabulary of Magnetism, 2016]], {accessed 2021-05-02})] | * [[magnetic flux density]] **//B//** - If //H// is present, then the $μ_0·H$ component is always present, and therefore increasing the excitation in a form of //H// will always produce an increase in the corresponding magnetic flux density //B// (when discussing amplitudes near saturation). Hence, it is also not possible to achieve some limiting value of "//B<sub>sat</sub>//" (and consequently there is no "saturation flux density" nor "saturation induction"). However, in practical cases it is sometimes useful to refer to the state of a material which is near saturation with some specific value of "//B<sub>sat</sub>//". Nevertheless, there is an implicit assumption that only some "technical saturation" is attained rather than full saturation. For example, in analysis of hysteresis loops of permanent magnets the "//B<sub>sat</sub>//" (or "//B<sub>s</sub>//") point could mean a state when just //J<sub>sat</sub>// was reached, even though //B// would continue to increase linearly beyond that point.[(Arnold>[[https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Vocabulary-of-Magnetism.pdf|Arnold Magnetic Technologies, TECHNotes, The Vocabulary of Magnetism, 2016]], {accessed 2021-05-02})] |
| | * in the CGS system the [[magnetic polarisation]] is referred to as [[intrinsic induction]], and therefore it is possible to have **saturation intrinsic induction** //B<sub>i,sat</sub>// which is typically just referred to as "saturation induction" //B<sub>sat</sub>// or //B<sub>s</sub>// even though it represents a different quantity from the ordinary induction[(Bozorth)] |
| * [[magnetisation]] **//M//** - The magnetisation //M// in (A/m) is the vector average of the individual magnetic moment over a given volume. Once all the individual moments are completely aligned with the applied excitation then full **saturation magnetisation //M<sub>sat</sub>//** is achieved. Further increase of magnetic excitation will //not// produce further increase of //M//, because full alignment was already achieved. | * [[magnetisation]] **//M//** - The magnetisation //M// in (A/m) is the vector average of the individual magnetic moment over a given volume. Once all the individual moments are completely aligned with the applied excitation then full **saturation magnetisation //M<sub>sat</sub>//** is achieved. Further increase of magnetic excitation will //not// produce further increase of //M//, because full alignment was already achieved. |
| * [[magnetic polarisation]] **//J//** - The value of polarisation //J// in (T) is the same quantity as //M// but scaled by the [[permeability of vacuum]] so that $J = μ_0 · M$, and therefore $J_{sat} = μ_0 · M_{sat}$. Therefore, there is also the limiting value of **saturation polarisation //J<sub>s</sub>//**. | * [[magnetic polarisation]] **//J//** - The value of polarisation //J// in (T) is the same quantity as //M// but scaled by the [[permeability of vacuum]] so that $J = μ_0 · M$, and therefore $J_{sat} = μ_0 · M_{sat}$. Therefore, there is also the limiting value of **saturation polarisation //J<sub>s</sub>//**. |
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| ==== Typical saturation values ==== | |
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| {{page>insert/todo}} | |
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| There are many magnetic materials ([[alloy|alloys]] and [[composite|composites]]) widely used in industry, for which well-established values of magnetic saturation are known. New reasearch | |
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| < table to be added here>[(YahaoLi>[[https://doi.org/10.1016/j.scriptamat.2024.116485|Yahao Li, Errui Jiang, Kaijia Hu, Yongqian Peng, Ziqi Ni, Fengqi Liu, Yicong Ye, Shun Li, Shuxin Bai, Active learning-enabled the discovery of ultra-high saturation magnetization soft magnetic alloys, Scripta Materialia, | |
| Vol. 257, 2025, 116485, https://doi.org/10.1016/j.scriptamat.2024.116485]])] | |
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| ^ Typical saturation polarisation //J<sub>sat</sub>// values [(Fiorillo)][(Cullity)][(YahaoLi)] ^^ | |
| | Fe70-Co25-Ni4-Si1 | 2.43 T | | |
| | Co49-Fe49-V2 | 2.35 T | | |
| | Fe | 2.15 T | | |
| | Co | 2.15 T | | |
| | Ni50-Fe50 | 1.60 T | | |
| | Ni36-Fe64 | 1.30 T | | |
| | Ni80-Fe15-Mo5 | 0.80 T | | |
| | Ni77-Fe14-Cu5-Mo4 | 0.78 T | | |
| | Ni | 0.608 T | | |
| | FeFe<sub>2</sub>O<sub>4</sub> | 0.603 T | | |
| | CoFe<sub>2</sub>O<sub>4</sub> | 0.534 T | | |
| | MnFe<sub>2</sub>O<sub>4</sub> | 0.503 T | | |
| | NiFe<sub>2</sub>O<sub>4</sub> | 0.340 T | | |
| | MgFe<sub>2</sub>O<sub>4</sub> | 0.151 T | | |
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