{'fraction_non_alphanumeric': 0.028307022318998367, 'fraction_numerical': 0.027218290691344585, 'mean_word_length': 4.853503184713376, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Performances of the racetrack memories of high density based on intermetallic compounds with high anisotropy in L10 phase

Materials with high uniaxial magnetocrystalline anisotropy were studied, used for ultrahigh density magnetic recording. We have determined the material properties considering different conditions of exploitation (different material compositions, structure characteristic dimensions and excitation fields). Our purpose was the optimal choice of structure and parameters which can ensure smaller magnetic domains having a maximum dynamics under the applied field. Alloys of FePt, CoPt, FePd in L10 phase on soft magnetic substrate have been analyzed, in thin layers 20 - 60 nm thick and 80 - 240 nm wide, with grain size of ca. 2.3-6 nm, using 3D simulation methods. Smaller grains are required for obtaining thinner domain walls in the recording media, but the sizes depend on the manufacturing methods and are physical limited by stability at thermal fluctuations. The grain sizes have not to be smaller than a threshold value, in order to keep the anisotropy. Areal densities of 100 - 900 Gbit/inch2 for recording have been obtained in the material magnetic media. The propagation current in the magnetic film was jc = (-1.5·1012 ... +1.5·1012) A/m12. Velocity of the domain wall motion was determined in function of the percent of the ordered phase, average grain size and anisotropy field in different material structures. Values between ca. 100 and 350 m/s have been obtained on the parametric curves, presenting maxima of interest when the ordered phase percent is not very high, between 0.62 and 0.76 (an advantage for the samples synthesizing) when the other parameters are correlated. Structure optimization can be made by simulation, in order to obtain the maximum storage capacity in a considered medium.