Magnetocaloric MnFeSiP Materials with Nitrogen for Mechanical Stability

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Solution Overview

Problem

Magnetocaloric materials comprising manganese, iron, silicon, and phosphorus lack mechanical stability during thermal or magnetic field cycling, leading to potential fractures and destruction, which is undesirable in technical applications.

Innovation Solution

Incorporating nitrogen into the magnetocaloric materials enhances mechanical stability, and optionally adding boron allows for adjustment of key parameters like Curie temperature, magnetic entropy change, and thermal hysteresis, while maintaining a hexagonal Fe2P structure with specific crystal lattice occupancy by nitrogen and boron atoms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If magnetocaloric materials comprising manganese, iron, silicon, and phosphorus are used, then magnetocaloric effect is achieved, but mechanical stability deteriorates during thermal or magnetic field cycling

Engineering Contradiction:

Improvemechanical stabilityVSAvoidresistance to fractures

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent applies parameter changes by introducing nitrogen atoms at interstitial sites and boron atoms at substitutional sites in the crystal lattice, fundamentally altering the material's structural parameters. This compositional modification transforms the material from mechanically unstable to mechanically stable during thermal and magnetic cycling, directly resolving the contradiction between achieving magnetocaloric effect and maintaining mechanical stability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by combining multiple elements (manganese, iron, silicon, phosphorus, nitrogen, and boron) with specific atomic ratios. The synergistic interaction between these elements, particularly nitrogen at interstitial positions and boron at substitutional positions, produces a composite structure that simultaneously achieves magnetocaloric functionality and enhanced mechanical stability during cycling operations

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If nitrogen and boron are added to adjust magnetic properties, then Curie temperature and magnetic entropy change are optimized, but material composition complexity increases

Engineering Contradiction:

ImproveCurie temperature controlVSAvoidcomposition complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by assigning nitrogen atoms to specific interstitial sites (6k or 6j positions) and boron atoms to specific substitutional sites (1b or 2c positions) in the hexagonal Fe2P crystal structure. This localized placement of different elements at specific crystallographic positions enables precise control over magnetic properties such as Curie temperature and magnetic entropy change, while maintaining a relatively simple overall composition framework

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by systematically varying the atomic ratios of nitrogen (0.01 ≤ z ≤ 0.1) and boron (0.04 ≤ w ≤ 0.08) to precisely tune magnetic parameters. By controlling the concentration of nitrogen at interstitial sites and boron at substitutional sites, the Curie temperature and magnetic entropy change can be optimized for specific applications, transforming composition complexity into a controllable parameter for performance optimization

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The presence of nitrogen improves mechanical stability, allowing the materials to remain intact during cooling in liquid nitrogen, and adjusting nitrogen and boron content optimizes magnetic properties, reducing thermal hysteresis and volume change during magnetic phase transitions.

Implementation Method 1

nitrogen atoms occupy interstitial sites of said crystal lattice

Methodology Applied

Scientific EffectInterstitial occupancy:

Implementation Method 2

boron atoms occupy crystal sites of said crystal lattice

Methodology Applied

Scientific EffectSubstitutional occupancy:

Implementation Method 3

Magnetocaloric materials are materials exhibiting a magnetocaloric effect, i.e. a temperature change caused by exposing said material to a changing external magnetic field

Methodology Applied

Scientific EffectMagnetocaloric effect: Magnetocaloric Effect

Data Source

PatentUS11139093B2Magnetocaloric materials comprising manganese, iron, silicon, phosphorus and nitrogen

Publication Date: 2021.10.05 MAGNETO BV

AI summary

The present invention relates to magnetocaloric materials comprising manganese, iron, silicon, phosphorus, nitrogen and optionally boron.