Tailoring Negative Thermal Expansion via Tunable Induced Strain in La–Fe–Si-Based Multifunctional Material

Abstract

Zero thermal expansion (ZTE) composites are typically designed by combining positive thermal expansion (PTE) with negative thermal expansion (NTE) materials acting as compensators and have many diverse applications, including in high-precision instrumentation and biomedical devices. La­(Fe1–x ,Si x )­13-based compounds display several remarkable properties, such as giant magnetocaloric effect and very large NTE at room temperature. Both are linked via strong magnetovolume coupling, which leads to sharp magnetic and volume changes occurring simultaneously across first-order phase transitions; the abrupt nature of these changes makes them unsuitable as thermal expansion compensators. To make these materials more useful practically, the mechanisms controlling the temperature over which this transition occurs and the magnitude of contraction need to be controlled. In this work, ball-milling was used to decrease particles and crystallite sizes and increase the strain in LaFe11.9Mn0.27Si1.29H x alloys. Such size and strain tuning effectively broadened the temperature over which this transition occurs. The material’s NTE operational temperature window was expanded, and its peak was suppressed by up to 85%. This work demonstrates that induced strain is the key mechanism controlling these materials’ phase transitions. This allows the optimization of their thermal expansion toward room-temperature ZTE applications.

Flexible Magnetocaloric Fiber Mats for Room-Temperature Energy Applications

“…Rietveld refinement was performed on the diffractogram of the LaFe 11.83 Mn 0.32 Si 1.28 H powder, and the result is presented in Figure c (Rietveld refinement parameters: R p : 1.51, R ωp : 2.34, and R exp : 0.02). The Rietveld refinement shows that LaFeSi grains crystallized in a cubic NaZn 13 -type structure with a minor amount of α-Fe phase (∼3%) as typically occurs in these materials. ,, The estimated volume and lattice parameters are 1546.115 (±0.006) Å 3 and 11.56327 (±0.00003) Å, respectively, and they are in agreement with the literature . It is important to remark that XRD was performed at room temperature (∼297 K), that is, at a temperature above LaFeSi’s T c .…”

“…The Rietveld refinement shows that LaFeSi grains crystallized in a cubic NaZn 13 -type structure with a minor amount of α-Fe phase (∼3%) as typically occurs in these materials. 20,59,60 The estimated volume and lattice parameters are 1546.115 (±0.006) Å 3 and 11.56327 (±0.00003) Å, respectively, and they are in agreement with the literature. 61 It is important to remark that XRD was performed at room temperature (∼297 K), that is, at a temperature above LaFeSi's T c .…”

Long-stable solar energy capture and storage via negative thermal expansion regulated calcium-based particles

“…The NTEP is used as a thermal expansion compensator, which greatly slows down the effect of reducing the yield of adsorbed CO 2 due to volume expansion and blocking the channel to achieve the behavior role of control of calcium oxide in the carbonation reaction. 33 Fig. 1(b) shows the linear thermal expansion curves of the calcium-based material before and after doping with NTEP.…”

Bioactive Magnetic Materials in Bone Tissue Engineering: A Review of Recent Findings in CaP‐Based Particles and 3D‐Printed Scaffolds

“…[64,81] The most often used top-down methods for the synthesizing of MNP include ball milling, electron beam deposition, laser ablation, and sputtering, while thermal decomposition, coprecipitation, hydrothermal, and sol-gel techniques have been the most studied bottom-up techniques. [90,[95][96][97] Physical methods are inherently simpler processes that rely on the removal, division, and downsizing of bulk material and are favored for large-scale manufacturing of NP. However, the imperfection of the surface structure and the achievement of suitable characteristics are some of the most significant drawbacks of this route of manufacturing.…”

“…[ 64,81 ] The most often used top‐down methods for the synthesizing of MNP include ball milling, electron beam deposition, laser ablation, and sputtering, while thermal decomposition, coprecipitation, hydrothermal, and sol–gel techniques have been the most studied bottom‐up techniques. [ 90,95–97 ]…”