Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

13. 벼잎선충의 약제처리 방법별 방제 효과

The exchange bias effect, discovered more than fifty years ago, is a fundamental interfacial property, which occurs between ferromagnetic and antiferromagnetic materials. After intensive experimental and theoretical research over the last ten years, a much clearer picture has emerged about this effect, which is of immense technical importance for magneto-electronic device applications. In this review we start with the discussion of numerical and analytical results of those models which are based on the assumption of coherent rotation of the magnetization. The behavior of the ferromagnetic and antiferromagnetic spins during the magnetization reversal, as well as the dependence of the critical fields on characteristic parameters such as exchange stiffness, magnetic anisotropy, interface disorder etc. are analyzed in detail and the most important models for exchange bias are reviewed. Finally recent experiments in the light of the presented models are discussed.

Exchange Bias Effect of Ferro-/Antiferromagnetic Heterostructures

Resonant (elastic) soft x-ray scattering (RSXS) offers a unique element, site, and valence specific probe to study spatial modulations of charge, spin, and orbital degrees of freedom in solids on the nanoscopic length scale It cannot only be used to investigate single crystalline materials This method also enables to examine electronic ordering phenomena in thin films and to zoom into electronic properties emerging at buried interfaces in artificial heterostructures During the last 20 years, this technique, which combines x-ray scattering with x-ray absorption spectroscopy, has developed into a powerful probe to study electronic ordering phenomena in complex materials and furthermore delivers important information on the electronic structure of condensed matter This review provides an introduction to the technique, covers the progress in experimental equipment, and gives a survey on recent RSXS studies of ordering in correlated electron systems and at interfaces

Resonant Elastic Soft X-Ray Scattering

Resonant (elastic) soft x-ray scattering (RSXS) offers a unique element, site and valence specific probe to study spatial modulations of charge, spin and orbital degrees of freedom in solids on the nanoscopic length scale. It is not only used to investigate single-crystalline materials. This method also enables one to examine electronic ordering phenomena in thin films and to zoom into electronic properties emerging at buried interfaces in artificial heterostructures. During the last 20 years, this technique, which combines x-ray scattering with x-ray absorption spectroscopy, has developed into a powerful probe to study electronic ordering phenomena in complex materials and furthermore delivers important information on the electronic structure of condensed matter. This review provides an introduction to the technique, covers the progress in experimental equipment, and gives a survey on recent RSXS studies of ordering in correlated electron systems and at interfaces.

https://iopscience.iop.org/article/10.1088/0034-4885/76/5/056502/pdf

Resonant elastic soft x-ray scattering

The experimental endstation of the hard X-ray beamline BL9 of the Dortmund Electron Accelerator is equipped with a Huber six-circle diffractometer. It is dedicated to grazing-incidence X-ray diffraction and X-ray reflectivity experiments on solid surfaces and thin films as well as to powder diffraction measurements. A new set-up for grazing-incidence X-ray scattering of liquids has been built up using a silicon mirror to reflect the incident X-ray to the liquid surface at angles of incidence around the critical angle of total reflection of the sample. X-ray reflectivity measurements of a polymer film and grazing-incidence X-ray diffraction measurements of an epitaxically grown Gd40Y60 film, an oxidized surface of Fe-15at.%Al alloy and aqueous salt solutions are presented and discussed.

The new diffractometer for surface X‐ray diffraction at beamline BL9 of DELTA

In superconducting spin valves of the type S/F1/N/F2 or F1/S/F2 with a superconducting layer S, two ferromagnetic layers F1 and F2, and a normal metallic layer N, the superconducting transition temperature ${T}_{\text{S}}$ depends on the relative magnetization direction of the ferromagnetic layers F1 and F2. The difference of the transition temperature $\ensuremath{\Delta}{T}_{\text{S}}={T}_{s}^{\text{AP}}\ensuremath{-}{T}_{s}^{\text{P}}$ with the magnetization direction of F1 and F2 either antiparallel or parallel is called the superconducting spin valve effect. We have prepared both types of spin valves by growing Fe/V thin-film heterostructures with epitaxial quality on MgO(001) substrates. In the S/F1/N/F2-type spin valves the ferromagnetic layers were the first two Fe layers of a [Fe/V] superlattice coupled antiferromagnetically via the interlayer exchange interaction. Here we observed a superconducting spin valve shift of up to $\ensuremath{\Delta}{T}_{\text{S}}\ensuremath{\approx}200\text{ }\text{mK}$ when aligning the sublattice magnetization in an external magnetic field. In the F1/S/F2-type spin valves the ferromagnetic layer F1 was either a [Fe/V] or a $[{\text{Fe}}_{x}{\text{V}}_{1\ensuremath{-}x}/\text{V}]$ superlattice, the F2 layer was a Fe-, a Co-, or a ${\text{Fe}}_{x}{\text{V}}_{1\ensuremath{-}x}$ film. Using weakly ferromagnetic ${\text{Fe}}_{x}{\text{V}}_{1\ensuremath{-}x}$ alloy layers as F1 and F2 we find a spin valve effect of up to $\ensuremath{\Delta}{T}_{\text{S}}\ensuremath{\approx}20\text{ }\text{mK}$, which is more than a factor of 2 larger than reported in the literature before for spin valves with comparable transition temperatures. Our results indicate that a high interface transparency and a large superconducting correlation length are prerequisites for the observation of a sizable superconducting spin valve effect.

/pdf/superconducting-spin-valves-based-on-epitaxial-fe-v-5ctpumzhqw.pdf

Superconducting spin valves based on epitaxial Fe/V superlattices

https://arxiv.org/pdf/cond-mat/0505482.pdf

Soft X-ray resonant magnetic scattering studies on Fe/CoO exchange bias system

We have employed soft and hard x-ray resonant magnetic scattering and polarized neutron diffraction to study the magnetic interface and the bulk antiferromagnetic domain state of the archetypal epitaxial ${\text{Ni}}_{81}{\text{Fe}}_{19}(111)/\text{CoO}(111)$ exchange biased bilayer. The combination of these scattering methods provides unprecedented detailed insights into the still incomplete understanding of some key manifestations of the exchange bias effect. We show that the several orders of magnitude difference between the expected and measured value of exchange bias field is caused by an anisotropic in-plane orientation of antiferromagnetic domains. Irreversible changes in their configuration lead to a training effect. This is directly seen as a change in the magnetic half-order Bragg peaks after magnetization reversal. The antiferromagnetic domain size is extracted from the width of the $(\frac{1}{2}\frac{1}{2}\frac{1}{2})$ antiferromagnetic peak by both neutron and x-ray scattering and is determined to be 30 nm in size. A reduced blocking temperature as compared to the measured antiferromagnetic ordering temperature clearly corresponds to the blocking of antiferromagnetic domains. Moreover, an excellent correlation between the size of the antiferromagnetic domains, exchange bias field, and frozen-in spin ratio is found, providing a comprehensive understanding of the origin of exchange bias in epitaxial systems.

Origin of the reduced exchange bias in an epitaxial FeNi(111)/CoO(111) bilayer

X-ray amorphous thin films of the Heusler alloys Cu2MnAl and Co2MnSi have been prepared by magnetron sputter deposition at room temperature. In the amorphous state the Cu2MnAl phase is non-ferromagnetic; Co2MnSi is weakly ferromagnetic with a ferromagnetic Curie temperature of 170?K. By solid-state crystallization at high temperatures strong ferromagnetic order and high Curie temperatures are established in both alloys. The saturation magnetization of the Co2MnSi alloy reaches 5.1?B/f.u. at 4?K, corresponding to 100% of the theoretical value; for Cu2MnAl we obtain 2.8?B/f.u. at 4?K, which corresponds to 87.5% of the theoretical value. In samples of the Co2MnSi phase with optimum saturation magnetization Bragg reflections as indicators of a long-range chemical order are missing, whereas for the Cu2MnAl phase Bragg reflections confirm epitaxial quality and long-range L21 order.

/pdf/thin-films-of-the-heusler-alloys-cu2mnal-and-co2mnsi-y91jrasrff.pdf

Gregor Nowak

Papers

The new diffractometer for surface X‐ray diffraction at beamline BL9 of DELTA

Superconducting spin valves based on epitaxial Fe/V superlattices

Soft X-ray resonant magnetic scattering studies on Fe/CoO exchange bias system

Origin of the reduced exchange bias in an epitaxial FeNi(111)/CoO(111) bilayer

Thin films of the Heusler alloys Cu2MnAl and Co2MnSi: recovery of ferromagnetism via solid-state crystallization from the x-ray amorphous state