Related Experiment Video
Updated: May 1, 2026
08:55
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.2K
Taming the first-order transition in giant magnetocaloric materials
François Guillou1, Giacomo Porcari, Hargen Yibole
1Fundamental Aspects of Materials and Energy (FAME), Delft University of Technology, Mekelweg 15, 2629, JB, Delft, The Netherlands.
Advanced Materials (Deerfield Beach, Fla.)
|March 29, 2014
Summary
Researchers discovered that adjusting Boron (B) content in Manganese Iron Phosphide Silicide (MnFe(P,Si)) materials optimizes magnetocaloric properties. These materials exhibit significant temperature changes, making them ideal for efficient magnetic refrigeration applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Thermodynamics
Background:
- Magnetocaloric materials are crucial for developing next-generation magnetic refrigeration technologies.
- Manganese Iron Phosphide Silicide (MnFe(P,Si)) based compounds have shown potential due to their large magnetocaloric effects.
- Controlling the phase transition and associated properties is key to enhancing their performance.
Purpose of the Study:
- To investigate the effect of partial Boron (B) substitution for Phosphorus (P) in MnFe(P,Si) compounds.
- To optimize magnetocaloric properties by tuning the latent heat at the Curie point.
- To assess the suitability of these modified materials for magnetic refrigeration.
Main Methods:
- Synthesis and characterization of MnFe(P,Si,B) compounds with varying B content.
- Magnetic and thermal measurements to determine temperature changes, entropy changes, and hysteresis.
- Evaluation of mechanical stability and Curie point characteristics.
Main Results:
- Large magnetically driven temperature and entropy changes were observed in MnFe(P,Si,B) materials.
- Partial substitution of B for P effectively controlled the latent heat at the Curie point.
- Limited thermal and magnetic hysteresis, along with good mechanical stability, were achieved.
Conclusions:
- The partial substitution of Boron (B) for Phosphorus (P) is an effective strategy to tune the magnetocaloric properties of MnFe(P,Si) compounds.
- Optimized MnFe(P,Si,B) materials exhibit promising magnetocaloric performance suitable for magnetic refrigeration.
- These findings pave the way for the development of efficient and stable magnetic cooling devices.
Related Concept Videos
01:31Ferromagnetism
2.8K
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...
2.8K
01:30Paramagnetism
2.4K
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...
2.4K
01:28Types Of Superconductors
1.7K
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...
1.7K
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.1K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.1K
01:24Potential Due to a Magnetized Object
924
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
The vector...
924
01:28Magnetostatic Boundary Conditions
1.9K
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
1.9K