Microstructure and Magnetocaloric Effect by Doping C in La-Fe-Si Ribbons.
Huihui Song1, Yuhu Hu1, Jiale Zhang1
1School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China.
Materials (Basel, Switzerland)
|January 11, 2022
Summary
Carbon doping in LaFeSi compounds enhances magnetic properties. Optimized annealing of LaFe11.5Si1.5C0.2 ribbons yields a significant magnetic entropy change of 9.45 J/(kg·K) at 255 K.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Magnetism
Background:
- La(Fe,Si)13 compounds are promising magnetocaloric materials.
- Carbon doping can influence phase formation and magnetic properties.
Purpose of the Study:
- To investigate the effect of carbon doping on the structure and magnetic properties of LaFe11.5Si1.5 compounds.
- To optimize annealing conditions for enhanced magnetocaloric performance.
Main Methods:
- Melt fast-quenching technique for ribbon preparation.
- Microstructure observation and elemental analysis.
- Annealing studies at varying times and temperatures.
- Magnetic property measurements, including isothermal magnetic entropy change and Curie temperature determination.
Main Results:
- Carbon doping promotes the formation of the desired La(Fe,Si)13 phase.
- Annealing LaFe11.5Si1.5C0.2 at 1273 K for 2 hours resulted in optimal magnetic properties.
- A maximum isothermal magnetic entropy change of 9.45 J/(kg·K) was achieved under a 1.5 T field.
- The Curie temperature was increased to 255 K.
Conclusions:
- Carbon doping is beneficial for the synthesis of La(Fe,Si)13 based magnetocaloric materials.
- Optimized annealing significantly enhances the magnetocaloric effect and Curie temperature.
- These findings contribute to the development of efficient magnetic refrigeration materials.
Keywords:
annealingmagnetocaloric effectmaximum isothermal magnetic entropymicrostructurerapid solidificationMore Related Videos
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.2K
11:11Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation
Published on: May 2, 2016
11.2K
Related Concept Videos
01:31Ferromagnetism
2.5K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.5K
01:28Types Of Superconductors
1.2K
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
1.2K
01:26Diamagnetism
2.5K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.5K
01:30Paramagnetism
2.6K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.6K
01:17Theory of Metallic Conduction
1.5K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.5K
01:27Biasing of Metal-Semiconductor Junctions
361
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
361