Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain
X. Moya, L. E. Hueso, F. Maccherozzi, A. I. Tovstolytkin, D. I. Podyalovskii, C. Ducati, L. C. Phillips, M. Ghidini, O. Hovorka, A. Berger, M. E. Vickers, E. De… 展开作者
X. Moya, L. E. Hueso, F. Maccherozzi, A. I. Tovstolytkin, D. I. Podyalovskii, C. Ducati, L. C. Phillips, M. Ghidini, O. Hovorka, A. Berger, M. E. Vickers, E. Defaÿ, S. S. Dhesi, N. D. Mathur
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32 pages, 1 Table, 5 figures, supplementary information
Large thermal changes driven by a magnetic field have been proposed for environmentally friendly energy efficient refrigeration, but only a few materials which suffer hysteresis show these giant magnetocaloric effects. Here we create giant and reversible extrinsic magnetocaloric effects in epitaxial films of the ferromagnetic manganite La0.7Ca0.3MnO3 using strain mediated feedback from BaTiO3 substrates near a first-order structural phase transition. Our findings should inspire the discovery of giant magnetocaloric effects in a wide range of magnetic materials, and the parallel development of nanostructured bulk samples for practical applications.
Reversible tuning of magnetocaloric Ni-Mn-Ga-Co films on ferroelectric PMN-PT substrates
通过机械应力调节热薄膜的功能特性是当前的高度兴趣。特别地，期望可控的磁化或转变温度以改善磁热装置中的可用性。在这里，我们提出的结果外延磁热Ni-Mn-Ga-Co薄膜的铁电Pb（Mg $_{1/3}$ Nb $_{2/3}$）$_{0.72}$ Ti $_{0.28}$ O $_3$（PMN-PT）衬底。利用X射线衍射测量，我们表明，通过施加电场在衬底中引起的应变可以转移到薄膜，导致晶格参数的变化。我们研究的后果，这种应变的磁性薄膜的温度和电场依赖的测量。我们没有观察到马氏体相变温度的变化，但在奥氏体状态下，我们归因于这种变磁性Heusler合金的内在磁不稳定性的磁化强度的可逆变化。
Improved magnetostructural and magnetocaloric reversibility in magnetic Ni-Mn-In shape-memory Heusler alloy by optimizing the geometric compatibility condition
本文报道了磁性形状记忆合金Ni $_{1.8}$ Mn $_{1.8}$ In $_{0.4}$的磁致伸缩可逆性和逆磁热效应的改善。我们表明，磁致伸缩和MCE的关键取决于奥氏体和马氏体相的几何相容性。从X射线衍射数据计算的变换矩阵中获得了关于两相相容性的详细信息。晶格参数的唯一性导致磁致伸缩和MCE的可逆性改善。在马氏体相变的热滞区，脉冲磁场作用下的最大相对长度变化为0.3%，绝热温度变化为$ΔT_{ad}\approx -10$ K。我们的研究结果表明，几何相容性的方法将允许一个设计材料的可逆磁致伸缩和可逆逆MCE在一阶磁结构相变的形状记忆Heusler合金。
Reversible intrinsic-extrinsic crossover of the anomalous Hall effect in PrAlSi via Al/Si ratio tuning
Jiangxi University of Science and Technology（江西理工大学）；National Rare Earth Functional Materials Innovation Center, Jiangxi University of Science and Technology（江西稀土功能材料创新中心）
Fostering Innovation: Streamlining Magnetocaloric Materials Research by Digitalization
Federal Institute for Materials Research and Testing（联邦材料研究与测试研究所）；Faculty of Technology and CITEC, Bielefeld University（比勒费尔德大学技术与CITEC学院）；Faculty of Physics, Bielefeld University（比勒费尔德大学物理学院）；Helmholtz-Zentrum Berlin for Materials and Energy（柏林亥姆霍兹材料与能源中心）；Bielefeld Institute for Applied Materials Research, Bielefeld University of Applied Sciences and Arts（比勒费尔德应用材料研究所，比勒费尔德应用技术大学）
Effect of chemical and hydrostatic pressure on the coupled magnetostructural transition of Ni-Mn-In Heusler alloys
Ni-Mn-In磁性形状记忆Heusler合金在其一级马氏体相变时普遍存在较大的热滞，这阻碍了其在磁制冷领域的应用。通过优化Ni $_2$ Cu $_x$ Mn $_{1.4-x}$ In $_{0.6}$中的Cu含量，得到了Ni $_{2}$ Cu $_{0.2}$ Mn $_{1.2}$ In $_{0.6}$中马氏体相变的热滞仅为6 K。我们可以解释这个非常小的滞后马氏体和奥氏体相的界面处的一个几乎完美的惯习平面。流体静压的应用不会进一步降低滞后，但将马氏体转变移到接近室温。等温熵变不依赖于加热或冷却协议，并且与压力无关。在脉冲磁场下对Ni $_{2}$ Cu $_{0.2}$ Mn $_{1.2}$ In $_{0.6}$的磁热效应进行了研究，发现其最大绝热温度变化为-13 K.
Extremely Large Magnetic Entropy Changes, Quantum Phases, Transitions and Diagram in Gd(OH)3 Single Crystal Nanowires - Quasi-1D Large Spin (S = -7/2) Chain Antiferromagnet
