Article
Chemistry, Multidisciplinary
Nina Popov, Marko Boskovic, Marija Perovic, Zoltan Nemeth, Junhu Wang, Zhichong Kuang, Michael Reissner, Erno Kuzmann, Zoltan Homonnay, Shiro Kubuki, Marijan Marcius, Mira Ristic, Svetozar Music, Dalibor Stankovic, Stjepko Krehula
Summary: Cobalt doping resulted in gradual elongation and thinning of hematite nanorods, significant changes in optical and magnetic properties, and enhanced electrocatalytic activity for the oxygen evolution reaction compared to pure hematite nanorods.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Geochemistry & Geophysics
Alexandra Abrajevitch, Andrew P. Roberts, Brad J. Pillans, Rie S. Hori
Summary: Hematite is a commonly occurring magnetic mineral with unique magnetic properties, exhibiting oscillating remanence states after thermal cycling, likely due to sublattice magnetization alignment switches. These observations provide new insights into the magnetism of hematite.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Materials Science, Multidisciplinary
Irina S. Edelman, Ruslan D. Ivantsov, Chun-Rong Lin, Sergey M. Zharkov, Dmitry A. Velikanov, Maxim S. Molokeev, Galina M. Zeer, Ying-Zhen Chen, Aleksandr A. Spivakov
Summary: This study investigates the effects of low concentrations of chromium doping on the morphology and magnetic properties of hematite nanoparticles. It is found that the morphology and magnetic properties of the nanoparticles change significantly with increasing chromium concentration.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Multidisciplinary Sciences
Nandita Deb, Rimi Rashid, H. Das, Ishtiaque M. Syed, S. Manjura Hoque
Summary: In this study, nano-scale alpha-Fe2O3 particles were prepared using a hydrothermal technique and functionalized with chitosan. The results showed that the alpha-Fe2O3 nanoparticles had a single-phase structure with expected lattice constants and grain size. Additionally, the chitosan-coated particles exhibited a high zeta potential. Cell culture and hyperthermia experiments demonstrated that the nanohybrids had high maximum temperature and specific loss power within a certain concentration range.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Physics, Applied
Qiangqiang Zhang, Zhuhong Liu, Xingqiao Ma
Summary: A magnetic transition from ferromagnetism to ferrimagnetism occurs in hexagonal alloy Mn2.1FeSn0.9, with a small energy difference between the two phases that can be suppressed by a magnetic field. The coexistence of ferrimagnetic and ferromagnetic phases causes a large exchange bias field, leading to changes in physical properties during the transition, illustrating the easy regulation of the alloy's properties by magnetic structure.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Nina Popov, Stjepko Krehula, Mira Ristic, Erno Kuzmann, Zoltan Homonnay, Marko Boskovic, Dalibor Stankovic, Shiro Kubuki, Svetozar Music
Summary: The study investigated the impact of different levels of Cr doping on the properties of hematite nanorods, confirming the effect of Cr3+-for-Fe3+ substitution in the crystal structure and the enhancement of visible light photocatalytic activity induced by Cr doping.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Physics, Applied
Daisuke Kan, Takahiro Moriyama, Ryotaro Aso, Shinji Horai, Yuichi Shimakawa
Summary: We grew epitaxial thin films of hematite on Al2O3 substrates and investigated their magnetic properties. The films undergo Morin transition at higher temperatures when grown at lower temperatures. The magnetic properties were characterized by spin Hall magnetoresistance, revealing tri-axial magnetic anisotropy and large changes in SMR ratio associated with Neel vector re-orientation due to Morin transition.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Jin Yang, Rui Jiang, Shuai Huang, Dexuan Huo
Summary: The YCr0.5Fe0.5O3 ceramics with different sintering temperatures exhibit changes in structural, magnetic, and dielectric properties as the grain size decreases with lower sintering temperatures. The competition between single ion magnetic anisotropy and antisymmetric Dzyaloshinsky-Moriya interaction leads to size-dependent total magnetization behavior at the compensation temperature. Adjusting the magnetic field affects the compensation temperature, resulting in a positive exchange bias effect.
RESULTS IN PHYSICS
(2021)
Article
Chemistry, Physical
R. N. Bhowmik, R. J. Choudhary, Priyanka Mitra, V. R. Reddy, A. K. Sinha
Summary: The study demonstrates the enhancement of ferromagnetic properties in Ga doped hematite thin films grown using Pulsed Laser Deposition technique, with unusual magnetic spin order and exchange bias effect observed at reduced dimensions (2D). Magnetic parameters such as magnetization and coercivity show dependence on composition, deposition conditions, and heat treatment. The chemical states of Fe ions in the films vary between high spin Fe3+ and Fe2+ states based on composition.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
R. S. Silva Jr, J. Gainza, J. E. Rodrigues, L. Martinez, E. Cespedes, N. M. Nemes, J. L. Martinez, J. A. Alonso
Summary: In this study, FexTi2S4 polycrystalline materials were prepared using a rapid high-pressure method, and their crystal structure and magnetic properties were investigated. The results revealed a Fe/Ti inversion in the TiS2 layers and different magnetic behaviors depending on the Fe content. Furthermore, the material exhibited better relative cooling power and temperature stability compared to other transition metal sulfides reported in the literature.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Bibekananda Das, Prahallad Padhan
Summary: This study achieved dual sign magnetoresistance and a spin-glass state by stabilizing a thin film on a silicon substrate. The presence of a spin-glass state was attributed to competing double exchange and superexchange interactions. The thickness of the ZnO film influenced the magnetoresistance properties and magnetism behavior.
Article
Physics, Multidisciplinary
Dapeng Zhu, Tianrui Zhang, Xiao Fu, Runrun Hao, Amir Hamzic, Huaiwen Yang, Xueying Zhang, Hui Zhang, Ao Du, Danrong Xiong, Kewen Shi, Shishen Yan, Shufeng Zhang, Albert Fert, Weisheng Zhao
Summary: Recent studies have shown that antiferromagnetic insulators efficiently support spin current. In this study, we observe a strong temperature dependence and reversed sign of dampinglike spin-orbit torque (SOT) in Pt/NiO/CoFeB, which is different from the slight variation with temperature observed in Pt/CoFeB bilayer. The negative dampinglike SOT at low temperatures is proposed to be mediated by magnetic interactions tied to the "exchange bias" in Pt/NiO/CoFeB, in contrast to the thermal-magnon-mediated scenario at high temperatures. These results highlight the potential to control SOT by tuning the magnetic structure in multilayers.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Pelayo Garcia Acevedo, Manuel A. Gonzalez Gomez, Angela Arnosa Prieto, Jose S. Garitaonandia, Yolanda Pineiro, Jose Rivas
Summary: In this study, the synthesis and study of iron-oxide-based hollow MNPs and their precursors were conducted to investigate the mechanisms involved in exchange bias generation. The effects of external parameters on the properties of hollow MNPs were also examined. The presence of surface spins was proven to be crucial for exchange bias generation.
Article
Physics, Applied
Kyuhwe Kang, Won-Bin Lee, Dong-Kyu Lee, Kyung-Jin Lee, Gyung-Min Choi
Summary: The study demonstrates that a short-pulsed spin current can induce fast dynamics of metallic antiferromagnets via spin-transfer torque on the magnetization of sublattices, using two methods to generate the spin current. Results provide evidence of the direct interaction between the magnetization of antiferromagnets and spin current.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
A. A. Zvyagin, V. V. Slavin
Summary: This article discusses the stability of quantum spin-1 chain materials and their relationship to spin nematic ordering. The study found that spin nematic ordering is related to the spin subsystem's spin nematic order parameter, coupling to the elastic subsystem of the crystal, and interaction with ultracold bosons in a one-dimensional optical lattice.
Review
Geosciences, Multidisciplinary
Andrew P. Roberts, David Heslop, Xiang Zhao, Hirokuni Oda, Ramon Egli, Richard J. Harrison, Pengxiang Hu, Adrian R. Muxworthy, Tetsuro Sato
Summary: The magnetic domain state of a material determines its magnetic properties. However, constraining the domain state of magnetic components within complex natural mineral assemblages is challenging. First-order reversal curve (FORC) diagrams have been developed as a diagnostic tool for domain state identification. Recent developments include enhanced domain state diagnosis, recognition of vortex state signatures, identification of magnetic anisotropy types, and machine learning approaches for optimal FORC distribution selection. Additionally, a new FORC measurement protocol enables identification of magnetically viscous particles and quantitative separation of magnetic mineral mixtures.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geochemistry & Geophysics
H. A. Sheikh, B. A. Maher, V Karloukovski, G. Lampronti, R. J. Harrison
Summary: This study reports the characterization of anthropogenic magnetic particulate matter collected from roadside Callistemon trees in Lahore, Pakistan. The researchers used first-order reversal curve (FORC) diagrams to differentiate between different sources of anthropogenic magnetic particles. The results showed that FORC fingerprints have the potential to identify and quantify the relative contributions from exhaust and non-exhaust emissions.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Even S. Nikolaisen, Richard Harrison, Karl Fabian, Nathan Church, Suzanne A. McEnroe, Bjorn Eske Sorensen, Christian Tegner
Summary: The anisotropy of remanent magnetization and magnetic susceptibility is predominantly controlled by the mineralogical parameters of the ferrimagnetic fraction in rocks. The study combines 'slice-and-view' FIB nano-tomography data analysis with micromagnetic modeling and single crystal hysteresis measurements to provide insights into the complex interaction between magnetization structure, shape, and crystallographic relations in natural magnetic particles. Magnetic modeling of natural magnetic particles is essential to extract anisotropic hysteresis parameters directly from the primary remanence carriers.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Z. Pastore, P. Lelievre, S. A. McEnroe, N. S. Church
Summary: Scanning Magnetic Microscopy (SMM) is an important magnetometry technique that helps us understand the origin of rock behavior. In this study, 3D magnetic vector inversion was used to quantify the remanent magnetization in a norite sample and it was found that the main source of magnetization is pyroxenes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Pengfei Xue, Liao Chang, Zhaowen Pei, Richard J. Harrison
Summary: The origin of giant magnetofossils has remained a mystery due to the absence of modern analogues. This study discovered abundant giant magnetofossils in North Atlantic marine sediments, not only during the Palaeocene-Eocene Thermal Maximum but also before and after this period. The findings suggest that giant biogenic magnetite crystals were not exclusively produced during ancient hyperthermal events.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Fan Bai, Liao Chang, Zhaowen Pei, Richard J. Harrison, Michael Winklhofer
Summary: By constructing micromagnetic models with realistic biogenic greigite particles, this study provides reliable magnetic criteria to detect biogenic greigite in a wide range of environmental and geological settings.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Suzanne A. McEnroe, Nathan Church, Karl Fabian, Marianne F. Stange, Antonius T. J. van Helvoort
Summary: This study provides a comprehensive analysis of mineralogical and rock magnetic data for 57 samples from the high magnetic anomaly area in the Stardalur Caldera in Iceland, confirming that the anomaly is due to an unusually high intensity of remanent magnetization carried by magnetite. The study also shows that the concentration of magnetite in the area is at most twice as high as that in typical basalts, and the efficiency of remanent magnetization acquisition is at least three times higher. However, the detailed mechanism for the extreme overefficiency of remanent magnetization acquisition remains a mystery.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Zhaowen Pei, Liao Chang, Pengfei Xue, Richard J. Harrison
Summary: This study presents a machine learning framework called MagNet for automated recognition and classification of magnetic mineral grains in microscopic images. The framework performs well in identifying and classifying magnetofossil nanoparticles and can be extended to process different types of mineral images. This tool is important for extracting key quantitative information of magnetic mineral populations within diverse samples for interpreting Earth and planetary processes.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Even S. Nikolaisen, Karl Fabian, Richard Harrison, Suzanne A. McEnroe
Summary: Anisotropy of magnetic susceptibility (AMS) is a commonly used method to assess various geological properties. The study reveals that the behavior and magnetic response of magnetite inclusions vary between single-domain (SD) and multi-domain particles.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Po-Yen Tung, Hassan A. Sheikh, Matthew Ball, Farhang Nabiei, Richard J. Harrison
Summary: A machine learning approach is proposed to identify unknown micro- and nano-sized mineral phases and unmix their overlapped chemical signals. The approach shows reliability and accuracy in synthetic mixture and real-world particulate matter samples, providing a significant improvement to mineralogical and chemical analysis.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Multidisciplinary Sciences
Richard J. M. Taylor, Steven M. Reddy, David W. Saxey, William D. A. Rickard, Fengzai Tang, Caue S. Borlina, Roger R. Fu, Benjamin P. Weiss, Paul Bagot, Helen M. Williams, Richard J. Harrison
Summary: Researchers have discovered magnetite inclusions in zircon grains from the Jack Hills, which potentially carry a record of Earth's magnetic field dating back 4.2 billion years ago. The magnetite may be secondary in nature, suggesting a younger magnetic record than the zircon's crystallization age. The study reveals that the formation of secondary magnetite and the remobilization of lead and iron occurred after 3.4 billion years ago. This finding provides new opportunities to enhance our understanding of the Archean geodynamo. Rating: 9 out of 10.
Article
Geochemistry & Geophysics
M. D. Lee, S. McEnroe, Z. Pastore, N. Church, P. Schmidt
Summary: Inverse modeling was conducted on the magnetic minerals in a thin section of Black Hill Norite in South Australia. The study revealed that the presence of magnetite lamellae or its proximity to ilmenite grains can result in changes in magnetic intensity and direction. The use of tabular arrays for modeling produced a closer match to the observed anomaly compared to singular volume models.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geochemistry & Geophysics
Annemarieke Beguin, Karl Fabian, Nathan S. S. Church, Suzanne A. A. McEnroe
Summary: This study establishes an improved method to distinguish demagnetizing effects from internal stress in natural magnetite samples based on temperature-dependent hysteresis measurements. It confirms that interface strain and partial oxidation in complex microstructures create large internal stress in magnetite minerals.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Meeting Abstract
Geochemistry & Geophysics
S. Sridhar, J. Ryan, A. J. King, H. C. Bates, C. I. O. Nichols, R. J. Harrison, J. F. J. Bryson
METEORITICS & PLANETARY SCIENCE
(2022)