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The dynamic response of magnetically ordered materials to an ultrashort external stimulus depends on microscopic parameters, such as magnetic moment, exchange, and spin–orbit interactions. Whereas it is well established that, in multicomponent magnetic alloys and compounds, the speed of demagnetization and spin switching processes has an element‐specific character, the magnetization damping was assumed to be a universal parameter for all constituent magnetic elements irrespective of their different spin–orbit couplings and electronic structure. Herein, experimental and theoretical evidence for an element‐specific magnetic damping parameter is provided by investigating the ultrafast magnetization response of a high‐anisotropy ferrimagnetic DyCo5 alloy to femtosecond laser excitation. Strikingly different demagnetization and remagnetization dynamics of Dy and Co magnetic moments is revealed by employing femtosecond laser pump–X‐ray magnetic circular dichroism probe measurements combined with atomistic spin dynamics (ASD) simulations using ab initio calculated parameters. These observations, fully corroborated by the ASD simulations, are linked to the element‐specific spin–orbit coupling strengths of Dy and Co, which are incorporated in the phenomenological magnetization damping parameters. These findings can be used as a recipe for tuning the speed and magnitude of laser‐driven magnetic processes and consequently allow control over various dynamic functionalities in multicomponent magnetic materials. [ABSTRACT FROM AUTHOR]

We document magnetic mineral diagenesis with high‐resolution magnetic susceptibility, hysteresis, isothermal remanent magnetization, and other rock magnetic measurements through a shallow sulfate‐methane transition (SMT) at Perseverance Drift—a high‐accumulation rate Holocene biosiliceous Antarctic marine sediment deposit. The structure of the SMT is defined with porewater measurements from the same core, allowing direct comparison. Dissolution of the detrital (titano)magnetite assemblage, with preferential dissolution of stochiometric magnetite, occurs in the upper SMT. Higher coercivity magnetic minerals dissolve more slowly, continuing to dissolve through the entire SMT and could be a source of ferric iron for microbial respiration following exhaustion of porewater sulfate, as suggested by accumulation of porewater ferrous iron below the SMT. Superparamagnetic ferrimagnetic mineral enrichment/depletion occurs in three phases through the SMT and is coupled tightly to the availability of dissolved ferrous iron relative to dissolved sulfide. High concentrations of authigenic remanence‐bearing iron sulfides, including greigite and hexagonal 3C pyrrhotite, which can be detected using remanence parameters but not in‐field concentration dependent parameters, accumulate in a transient horizon at the base of the SMT during this early diagenesis, where sulfide is present but limited relative to dissolved ferrous iron. Formation of this remanence‐bearing iron sulfide horizon is likely facilitated by continued iron reduction through the SMT. Nonsteady state perturbations that shift the porewater profile, such as changes in carbon flux or sedimentation rate, can lead to preservation of these transient horizons, much like well documented preservation of manganese oxide layers in marine sediments following similar shifts to porewater profiles. Key Points: Magnetic mineral diagenesis is studied in Antarctic sediments using high‐resolution porewater and rock magnetic dataMagnetic mineral dissolution and authigenesis is tightly coupled to dissolved sulfide and ferrous iron concentrationsRemanence‐bearing iron sulfides form below the sulfate‐methane transition and can be preserved following nonsteady state diagenesis [ABSTRACT FROM AUTHOR]

W‐type SrFe22+Fe163+O27 ferrite is a member of the hexagonal ferrite family and a potential permanent magnet material. However, its synthesis conditions are not fully understood yet. Samples were sintered either at 1400°C in air and quenched, or at 1300°C at reduced oxygen partial pressure. The precise stability conditions of this W‐type ferrite were investigated in the temperature range of 1200°C‐1400°C using thermogravimetry, XRD, and electron microscopy. At 1300°C, the ferrite is stable at oxygen partial pressures of -3.1≤logpO2≤-1.6. At more oxidizing conditions, the ferrite decomposes into M‐type ferrite and hematite, while at more reducing atmospheres Sr4Fe6O13 and magnetite are formed. The nonstoichiometry δ of SrFe18−δO27 was derived from thermal analysis data at 1300°C as function of oxygen partial pressure and was found to be mainly due to cation vacancies. Magnetization measurements show that this W‐type ferrite exhibits Ms = 103 emu/g at T = 4 K, which agrees well with a ferrimagnetic spin arrangement according to Gorter's model. As alternative, Zn‐substituted W‐ferrite was found to be stable in air at 1200°C with a large Ms = 123 emu/g at 4 K. [ABSTRACT FROM AUTHOR]

Abstract: The large amount of generated waste determines the importance of their valorization. Red mud is the residue of the Bayer process, which stored cumulative value raises 2.7 Bt. This paper describes an easy way to produce a ferrimagnetic glass‐ceramic frit, using bauxite residue, fly ash and glass cullet as raw materials. The synthesized frit consists of faceted and dendritic agglomerated crystals of magnetite and titanomagnetite embedded in a glass matrix, which exhibits a saturation magnetization (MS) of 6.3 emu/g, a remanent magnetization (MR) of 2.7 emu/g and a coercive field (HC) of 347 Oe. Furthermore, it presents Vickers hardness value of HV = 5.55 ± 0.16 GPa and fracture toughness value of KIC = 1.64 ± 0.34 MPa·m1/2. [ABSTRACT FROM AUTHOR]

A series of two types of stochastic magnetization jumps in K0.4[Cr(CN)6][Mn( R/ S)-pn]( R/ S)-pnH0.6 single crystals (pn = 1,2-diaminopropane) are reported. Large jumps appear on the demagnetization branch of the hysteresis loop at the critical value of the decreasing magnetic field. The correlation of the temperature dependence of jump magnetic field and the temperature dependence of magnetic anisotropy field indicates a contribution of magnetic anisotropy to nonlinear spin-soliton structure. Small magnetization jumps occur in both magnetization and demagnetization regimes. [ABSTRACT FROM AUTHOR]

A novel Heusler ferrimagnet Ti2MnAl film has been grown on Si(001) substrate using magnetron sputtering. Characteristics of its magnetic and transport properties reveal the spingapless- semiconductor (SGS) nature of the stoichiometric Ti2MnAl, in agreement with theoretical prediction. The asgrown SGS-like Ti2MnAl film demonstrated high Curie temperature, nearly compensated ferrimagnetic properties with small coercivity and low magnetization. It also showed semiconductor-like behavior at room temperature allowing good compatibility with commercial Si-based semiconductor. In this regards, Ti2MnAl film is a potential candidate material for spintronics application, especially for the minimization of energy consumption of device. [ABSTRACT FROM AUTHOR]

Ab initio DFT calculations, XRD, Moessbauer spectroscopy, and magnetization measurements reveal a ferrimagnetic ground state of MnFe3N in the space group P4/mmm. [ABSTRACT FROM AUTHOR]

Mn2FeReO6 is prepared by hot pressing of a stoichiometric mixture of Mn3O4, Fe3O4, and ReO2 (Pt capsule in multianvil press, 11 GPa, 1400 °C, 20 min). [ABSTRACT FROM AUTHOR]