Hard magnet topological semimetals in XPt3 compounds with the harmony of Berry curvature

Topological magnetic semimetals, like Co3Sn2S2 and Co2MnGa, display exotic transport properties, such as large intrinsic anomalous (AHE) due to uncompensated Berry curvature. The highly symmetric XPt3 compounds exhibit anti-crossing gapped nodal lines, a driving mechanism in the intrinsic Berry curvature Hall effects. Uniquely, these compounds contain two sets of gapped nodal lines that harmoniously dominate the Berry curvature in this complex multi band system. We calculate a maximum AHE of 1965 S cm-1 in the CrPt3 by first principles electronic structure. We have grown high-quality CrPt3 thin films with perpendicular magnetic anisotropy by magnetron sputtering and measured a robust AHE of 1750 S cm−1 for different sputtering growth conditions. Additionally, the cubic films display an easy magnetic axis along [111] direction. The facile and scalable fabrication of these materials is prime candidates for integration into topological devices.

Analysis and Modeling of Attractive Force Using an Electropermanent Magnet and Electromagnetic in a Novel Wobble Gripper

An electropermanent magnet (EM) can be fixed or rotated without applying the additional power of a wobble motor. This consists of a neodymium magnet and semi-hard magnet. A model to design a wobble motor for a wobble gripper without finite element analyses and to predict the attraction force according to the permanent magnet and current is necessary. In this paper, a force model is derived using distribution parameter and magnetic circuit analyses, including flux loss and fringing effects. It is not easy to design a complete magnetic circuit model considering the loss effects, but it can be constructed using a relatively straightforward method that simplifies the paths of leaked fluxes into arcs and straight lines. The model was verified by comparing the results of finite element analyses with measurements of two prototypes using internal and external fixed cases. The model properly predicts the attractive force between the rotor and stator and can be used in the initial design of a gripper that holds or rotates with the electropermanent magnet.

Efek Penambahan Fe3Mn7 Terhadap Sifat Fisis dan Mekanik α-Fe2O3

Abstrak: Preparasi dan karakterisasi pellet α-Fe2O3 dengan penambahan 0, 2, 5 dan 10 %wt. Fe3Mn7 berbasis pada materialalam telah berhasil dilakukan. Proses pencampuran serbuk α-Fe2O3 dan Fe3Mn7 dilakukan dengan menggunakan HEM. ºKemudian campuran serbuk dikasinasi pada suhu 1000C, dikompaksi pada 69 Pa hingga menjadi pellet dan disinter padasuhu 1000 ºC. Karakterisasi XRD menunjukkan adanya fasa dominan α-Fe2O3 dan fasa baru MnO2 dan Fe3O4. Densitas dankekerasan sampel meningkat secara linier seiring dengan kenaikan komposisi Fe3Mn7 yang ditambahkan. Sampel optimum3diperoleh pada sampel α-Fe2O3/10 %wt. Fe3Mn7 dengan nilai bulk density dan kekerasan masing-masing 4,98 g/cm and994,94 HV. Sampel ini termasuk dalam klasifikasi hard magnet dengan nilai magnetisasi saturasi, remanen dan koersivitasmasing-masing sebesar 24,0 emu/g, 10,3 emu/g dan 571,8 Oe.Kata kunci:. α-Fe2O3, Fe3Mn7, densitas, kekerasan, sifat magnetikAbstract: Preparation and characterization of α-Fe2O3 pellet with the addition of 0, 2, 5 and 10 %wt. Fe3Mn7 based on naturalmaterials have been successfully carried out. The process of mixing powder of α-Fe2O3 and Fe3Mn7 was performed usingºHEM. Then, the mix powders were calcined at temperature of 1000 C. After that, the powders were compacted at 69 Pa intopellet and sintered at temperature of 1000ºC. Characterization of XRD shows that the samples have major phase of α-Fe2O3and new phases of MnO2 and Fe3O4. The density and hardness samples increase linearly with increasing of Fe3Mn73composition. The optimum sample with α-Fe2O3/10 %wt. Fe3Mn7 has bulk density and hardness value of 4.98 g/cm and 994.94HV respectively. This sample is classified as semi-hard magnet with magnetization saturation, remanence and coercivity valueof 24.0 emu/g, 10.3 emu/g dan 571.8 Oe respectively.Keywords: α-Fe2O3, Fe3Mn7, density, hardness, magnetic properties