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

Diamond-like carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC is a semiconductor with a high mechanical hardness, chemical inertness, and optical transparency. This review will describe the deposition methods, deposition mechanisms, characterisation methods, electronic structure, gap states, defects, doping, luminescence, field emission, mechanical properties and some applications of DLCs. The films have widespread applications as protective coatings in areas, such as magnetic storage disks, optical windows and micro-electromechanical devices (MEMs).

/pdf/diamond-like-amorphous-carbon-3pczopr0z7.pdf

Diamond-like amorphous carbon

BiFeO3 is perhaps the only material that is both magnetic and a strong ferroelectric at room temperature. As a result, it has had an impact on the field of multiferroics that is comparable to that of yttrium barium copper oxide (YBCO) on superconductors, with hundreds of publications devoted to it in the past few years. In this Review, we try to summarize both the basic physics and unresolved aspects of BiFeO3 (which are still being discovered with several new phase transitions reported in the past few months) and device applications, which center on spintronics and memory devices that can be addressed both electrically and magnetically.

Physics and Applications of Bismuth Ferrite

http://experimentationlab.berkeley.edu/sites/default/files/AFMImages/butt_AFM.pdf

Force measurements with the atomic force microscope: Technique, interpretation and applications

We report a non-Pb piezoelectric ceramic system Ba(Ti(0.8)Zr(0.2))O(3)-(Ba(0.7)Ca(0.3))TiO(3) which shows a surprisingly high piezoelectric coefficient of d(33) approximately 620 pC/N at optimal composition. Its phase diagram shows a morphotropic phase boundary (MPB) starting from a tricritical triple point of a cubic paraelectric phase (C), ferroelectric rhombohedral (R), and tetragonal (T) phases. The high piezoelectricity of the MPB compositions stems from the composition proximity of the MPB to the tricritical triple point, which leads to a nearly vanishing polarization anisotropy and thus facilitates polarization rotation between 001T and 111R states. We predict that the single-crystal form of the MPB composition of the present system may reach a giant d(33) = 1500-2000 pC/N. Our work may provide a new recipe for designing highly piezoelectric materials (both Pb-free and Pb-containing) by searching MPBs starting from a TCP.

Large Piezoelectric Effect in Pb-Free Ceramics

The electrocaloric (EC) effect in normal ferroelectric copolymer P(VDF-TrFE) and in relaxor terpolymer P(VDF-TrFE-CFE) is described in the framework of a phenomenological appoach. The change of the dipolar entropy in the copolymer, derived earlier from dielectric measurements by means of the Maxwell relation, is analyzed in terms of the mean field expression for entropy, and is shown to be consistent with the dielectric data. In the terpolymer case, the entropy change determined recently by direct (EC) measurements is found to be in qualitative agreement with the predictions of the mesoscopic spherical model of relaxor ferroelectrics.

Electrocaloric Effect and Dipolar Entropy Change in Ferroelectric Polymers

We show that 2D exchange NMR in deuteron glasses allows for a direct determination of the intra-H-bond deuteron exchange in the double-minimum O–D---O potential as well as for a measurement of the Edwards-Anderson order parameter deep in the glassy phase where 1D NMR methods for order parameter determination fail. A very slow fluctuation in the H-bond double-minimum potential is detected, which averages the H-bond asymmetry and glassy order parameter out to zero at long enough times. Deuteron glasses thus show a frozen-in disorder at times tτerg, whereas for times long compared to τerg, ergodicity is restored.

https://iopscience.iop.org/article/10.1209/0295-5075/23/4/009/pdf

2D exchange NMR in deuteron glasses

Temperature dependences of the dielectric constant and of the helical pitch have been measured for the mixture 71.76 wt.% of 4-n-butiloxybenzylidene-4′-n-octylaniline, 12.92 wt.% of 4–4′-bis-n-heptyloxy-azoxybenzene and 15.32 wt.% of 4″-(2-methylbutylphenyl)-4′-(2-methylbutyl)-4-biphenylcarboxylate which is in the ferroelectric helicoidal smectic C* phase at room temperature. The anomalies close to the smectic C*-smectic A transition are of the same type as in DOBAMBC and cannot be understood in terms of the standard Landau free energy expansion.

A room temperature ferroelectric liquid crystal

93Nb NMR in the incommensurate and quasicommensurate phases of barium sodium niobate.

The mixed crystal Rb1-x(NH4)xH2PO4 is a frustrated H-bonded system where the local cluster polarization (describing the ordering of the protons between the two possible sites in the H-bonds) represents a random field which modulates the electric quadrupole coupling of nuclei with non-zero quadrupole moments In contrast to pure RbH2PO4 or NH4H2PO4 there is no sharp change of the NMR frequency or spin-lattice relaxation rate at any well defined transition temperature Instead one finds an inhomogeneous broadening of the NMR lines which continuously increases with decreasing temperature and which can be used to determine the random field characterizing the quasi-static cluster polarization distribution Spin-lattice relaxation measurements further allow for a determination of the random field autocorrelation function which turns out to be of the "stretched" exponential type The presence of 87Rb and O–D—O deuteron T1 minima in both deuterated and undeuterated crystals demonstrates the tremendous slowing down of the notion of the hydrogens between the two equilibrium sites in the O–H—O bonds due to the hierarchical nature of the cluster dynamics in the formation of the pseudo-spin glass state

Robert Blinc

Papers

Electrocaloric Effect and Dipolar Entropy Change in Ferroelectric Polymers

2D exchange NMR in deuteron glasses

A room temperature ferroelectric liquid crystal

93Nb NMR in the incommensurate and quasicommensurate phases of barium sodium niobate.

NMR in Random Fields: Glass Transition in Rb1-x(NH4)xD2PO4