Sr2FeMoO6 nanosized compound with dielectric sheaths for magnetically sensitive spintronic devices

Каланда, Н. А.; Kim, Dong-Hyun; Demyanov, S. E.; Yu, Seong‐Cho; Yarmolich, Marta; Петров, А. В.; Oh, Suhk Kun

doi:10.1016/j.cap.2017.10.018

Cited by 14 publications

(12 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There are numerous potential applications of the Sr 2 FeMoO 6–δ double perovskite (SFMO), such as energy‐independent magnetic random‐access memory (MRAM), magnetic read heads for hard‐disk drives, sensitive magnetic‐field sensors, electrodes for solid fuel elements, and others. For these applications, structurally perfect SFMO samples with high values of the Curie temperature, saturation magnetization ( М s ), spin polarization degree of conduction electrons ( P s ) are needed .…”

Section: Introductionmentioning

confidence: 99%

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr₂FeMoO_6–δ

Каланда

Garamus

Авдеев

et al. 2019

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

Single‐phase strontium ferromolybdate (Sr2FeMoO6–δ) samples with different degrees of the superstructural ordering of the Fe/Mo cations (P) are obtained from partially reduced SrFeO3–х, SrMoO4 precursors by the solid‐state technology. The study of the temperature dependences of the magnetization measured in the field‐cooling and zero‐field‐cooling modes indicated an inhomogeneous magnetic state of the samples. The presence of magnetic regions of different nature has also been revealed by the small‐angle neutron scattering. For the Sr2FeMoO6–δ samples with different P values and for all values of the magnetic field induction up to 1.5 T and of the scattering vector in the interval 0.1 > q > 0.002 Å−1, the analytical dependence I ∼ q–α obeys the Porod law (α ≈ 4), which corresponds to an object with a smooth and well‐marked surface and polydisperse grain size. Deviations from the Porod law in the q > 0.1 Å−1 region and a weakening of the neutron scattering in applied magnetic fields may be ascribed to magnetic inhomogeneities with diameters D < 6 nm, which are partially destroyed/oriented by magnetic fields В ≥ 1.5 T. It is established that the magnetic homogeneity of the Sr2FeMoO6–δ compound is enhanced with increasing superstructural ordering of the Fe/Mo cations.

show abstract

Section: Introductionmentioning

confidence: 99%

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr₂FeMoO_6–δ

Каланда

Garamus

Авдеев

et al. 2019

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

show abstract

“…Одним из условий существования высокой степени спиновой поляризации в SFMO является наличие сверхструктурного упорядочения катионов Fe/Mo (Р), расположенных в центрах октаэдров, в вершинах которых находятся анионы кислорода [7,8]. В идеальной структуре SFMO катионы железа и молибдена находятся в высокоспиновом состоянии и имеют валентность Fe 3+ (3d 5 ) и Mo 5+ (4d 1 ). В реальной структуре присутствуют антиструктурные точечные дефекты и анионные вакансии, что приводит к перераспределению электронной плотности и разрушает сверхструктурное упорядочение.…”

Section: Introductionunclassified

SMALL-ANGLE SCATTERING OF NEUTRONS ON Sr<sub>2</sub>FeMoO<sub>6–δ</sub> SAMPLES WITH DIFFERENT-DEGREE SUPERSTRUCTURAL ORDERING OF Fe/Mo CATIONS

Gurskii

Каланда²,

Ярмолич³

et al. 2020

Doklady Belorusskogo gosudarstvennogo universiteta informatiki

View full text Add to dashboard Cite

Single-phase Sr2FeMoO6-δ samples with different-degreesuperstructiral ordering Fe/Mo cations superstructural ordering (P, 76, 86 and 93 %) were obtained by the solid-phase technique. Based on the results of measuring the magnetic characteristics in the samples, we found that an increase in magnetization (26.41, 32.36 and 42.66 A·m2·kg–1), magnetic moment (1.33, 3.07 and 3.58 μB/f.u.) and Curie temperatures (422, 428 and 437 K) withparameter P (76, 86 and 93 %) can be explained by the presence of antistructural defects, as well as antiferromagnetic inclusions. This determines the redistribution of electron density, which is accompanied by the change in electronic configuration of a part of Fe/Mo cations. Based on the temperature dependences of the magnetic moment of the samples measured in ZFC and FC modes, and on small-angle polarized neutron scattering (SANS), we found that the samples are in a magnetically inhomogeneous state. An important result to mention is that we detected the difference between the slope of the SANS curves of samples with different oxygen content, which demonstrates a different microstructure of inhomogeneities. The main inhomogeneities are magnetic inclusions with the dimensions depending on the superstructural ordering of Fe/Mo cations. According to the Porod law, it was shown that the Sr2FeMoO6-δ samples with wave vector values 0.1 > q > 0.002 Å–1 contain polydisperse grains with a smooth surface. For q > 0.1 Å–1 a deviation from the Porod law is observed, confirming the presence of magnetic inhomogeneities with a diameter < 6 nm in the grains.

show abstract

“…Strontium ferromolybdate Sr 2 FeMoO 6– δ (SFMO) with the double perovskite structure has attracted a lot of attention because of possible applications in magnetic field sensors and other spintronic devices due to its half‐metallic characteristics with a 100% spin polarization, relatively high Curie temperature of 410–450 K, and large values of room temperature magnetoresistance (≈3–10%) in magnetic fields below 1 T . Moreover, SFMO, with its mixed oxygen ion and electronic conductivity, may be applied in gas sensors, as a cathode material in solid‐fuel cells, in membranes for the selective segregation of oxygen from gaseous mixtures, etc …”

Section: Introductionmentioning

confidence: 99%

Valence State of Iron and Molybdenum Cations under Conditions of Anionic Deficiency in Sr₂FeMoO_6–_δ

Каланда

Yarmolich

Kim

et al. 2019

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

The activation energy of oxygen diffusion in strontium ferromolybdate Sr2FeMoO6–δ is determined by the Merzhanov technique based on the temperature dependences of the oxygen desorption dynamics. The activation energy has a minimum value of 76.7 kJ mol−1 at δ = 0.005 and a maximum value of 156.3 kJ mol−1 at δ = 0.06. It is suggested that with an increase in the concentration of oxygen vacancies, an interaction occurs between them and the nearest cations, with the subsequent formation of associates of various types that are less mobile than the single anion vacancies. According to Mössbauer spectroscopy data, it has been established that the appearance of oxygen vacancies and their ordering contribute to the isomer shift, and some of the iron ions occupy the tetrahedral (or close to it) positions in the lattice. This indicates the formation of associates of oxygen vacancies. The results of X‐ray photoelectron spectroscopy (XPS) studies show that the increase in the concentration of oxygen vacancies results in a decrease of the Mo6+ and Fe2+ concentrations. At the same time, the number of Mo5+ and Fe3+ cations increases due to the redistribution of the electron density, and molybdenum cations in a different valence state (Mo4+) appear.

show abstract

Sr2FeMoO6 nanosized compound with dielectric sheaths for magnetically sensitive spintronic devices

Cited by 14 publications

References 33 publications

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr₂FeMoO_6–δ

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr₂FeMoO_6–δ

SMALL-ANGLE SCATTERING OF NEUTRONS ON Sr<sub>2</sub>FeMoO<sub>6–δ</sub> SAMPLES WITH DIFFERENT-DEGREE SUPERSTRUCTURAL ORDERING OF Fe/Mo CATIONS

Valence State of Iron and Molybdenum Cations under Conditions of Anionic Deficiency in Sr₂FeMoO_6–_δ

Contact Info

Product

Resources

About

Sr2FeMoO6 nanosized compound with dielectric sheaths for magnetically sensitive spintronic devices

Cited by 14 publications

References 33 publications

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr2FeMoO6–δ

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr2FeMoO6–δ

SMALL-ANGLE SCATTERING OF NEUTRONS ON Sr<sub>2</sub>FeMoO<sub>6–δ</sub> SAMPLES WITH DIFFERENT-DEGREE SUPERSTRUCTURAL ORDERING OF Fe/Mo CATIONS

Valence State of Iron and Molybdenum Cations under Conditions of Anionic Deficiency in Sr2FeMoO6–δ

Contact Info

Product

Resources

About

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr₂FeMoO_6–δ

Small‐Angle Neutron Scattering and Magnetically Heterogeneous State in Sr₂FeMoO_6–δ

Valence State of Iron and Molybdenum Cations under Conditions of Anionic Deficiency in Sr₂FeMoO_6–_δ