• Home
  • Wolfgang Friedrich Müller
Wolfgang Friedrich Müller

Wolfgang Friedrich Müller
Technische Universitaet Darmstadt, Germany · Materials and Geo Sciences

Dr.rer.nat., Habilitation

About

104
Publications
3,355
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,582
Citations
Citations since 2016
1 Research Item
218 Citations
20162017201820192020202120220102030
20162017201820192020202120220102030
20162017201820192020202120220102030
20162017201820192020202120220102030

Publications

Publications (104)
Conference Paper
Hydraulic stimulations are the primary means of developing subsurface reservoirs regarding the extent of fluid transport in them. The associated creation or conditioning of a system of hydraulic conduits involves a range of hydraulic and mechanical processes but also chemical reactions, such as dissolution and precipitation, may affect the stimulat...
Article
Seven eclogite samples from 223 to 584 m depths in the Chinese Continental Scientific Drilling main borehole (CCSD-H) in the Sulu ultrahigh-pressure metamorphic (UHPM) terrane, Eastern China, were studied by transmission electron microscopy (TEM), in order to characterise their microstructures. We observed, among others, omphacite, jadeitic diopsid...
Article
In the Western Alps, the ocean-derived Lago di Cignana Unit of the Piemonte Zone has experienced ultrahigh-pressure metamorphism. We have studied the minerals of two eclogite samples from this unit using transmission electron microscopy (TEM) in order to characterise their microstructures. These microstructures are the result of deformation, phase...
Article
The Ca-Na clinopyroxene omphacite and garnet are the defining minerals and main phases of eclogites. The theological properties of eclogites are dominated by the mechanical behaviour of omphacite. Omphacite can occur in an ordered structure with the space group P2/n and, above 800 degrees C, in a disordered structure with the space group C2/c. Most...
Article
Full-text available
The event of the rapid imbrication of the Eclogite Zone (Tauern Window, Austria) between its lower and upper tectonic units had caused unusual deformation microstructures in garnet, clinozoisite and titanite of a sample from the lower tectonic unit about 10 m distant from the shear zone. In order to see if there are similar effects in rocks from th...
Article
An eclogite sample from the Lower Schist Cover of the Tauern Window, only a few tens of metres distant from the intercalated Eclogite Zone, was studied by transmission electron microscopy. Garnet, titanite and clinozoisite reveal unusual deformation microstructures not reported before from natural occurrences. Garnet shows polygonisation into subgr...
Article
Full-text available
Deformed and recovered omphacite from an eclogite sample of the Lower Schist Cover of the Tauern Window was studied by conventional and high resolution transmission electron microscopy. The rock sample, which was used before for petrological investigations (Zimmermann & Franz, 1988) and radiometric age dating (Von Quadt et al., 1997), shows chain m...
Article
Exsolution and coarsening in Fe-free clinopyroxene of composition En45.1Di54.9 was studied at temperatures of 1300, 1200, and 1100°C, and annealing times between 10 min and 4320 h. Based on the wavelength of the exsolution lamellae, the exsolution process can be divided into exsolution sensu stricto and coarsening. During exsolution sensu stricto,...
Article
A systematic transmission electron microscopy (TEM) study was performed on the size distribution of antiphase domains in omphacite from eclogites from the Adula/Cima Lunga nappe. The measured mean antiphase domain size is shown to depend on peak temperature, duration of peak metamorphism, cooling rate, and composition. The systematics of the size d...
Article
Deformed omphacite from an eclogite sample of the Lower Schist Cover of the Tauern Window was studied by conventional and high resolution transmission electron microscopy. The formation conditions of this eclogite were 400 to 500 °C at 8 to 12 kbar (Zimmermann &Franz, 1988); radiometric age dating yielded a formation age of about 420 Ma (von Quadt...
Article
Full-text available
A metamorphosed ultramafic rock, penetrated by the KTB pilot hole at a depth of 1382.36 m, contains the assemblage Caamphibole - anthophyllite - chlorite - talc, formed at about 630degreesC/10 kbar under conditions of the high-P amphibolite facies. EMP analyses of the Ca-amphibole yielded magnesiohastingsite (to pargasite) compositions with (Al+Fe3...
Article
We present microstructural data and lattice preferred orientations (LPOs) of omphacites from a suite of eclogites, from the Adula/Cima Lunga nappe (Central Alps). Our work shows a surprisingly strong correlation between the measured LPO and the ordering state of cations in omphacite. Estimates of deformation temperature from metamorphic petrology,...
Article
Abstract— The microstructure of Fe-rich clinopyroxene from synthetic analogues of chondrules was studied by transmission electron microscopy. The samples were cooled at various rates from 1455 °C to the quench temperature of 1000 °C. Slow cooling at rates below approximately 50–60 °C/h leads to the development of coherent pigeonite/augite exsolutio...
Article
The microstructure of Fe-rich clinopyroxene from synthetic analogues of chondrules was studied by transmission electron microscopy. The samples were cooled at various rates from 1455 degreesC to the quench temperature of 1000 degreesC. Slow cooling at rates below approximately 50-60 degreesC/h leads to the development of coherent pigeonite/augite e...
Article
Full-text available
In the Erzgebirge Crystalline Complex, eclogites occur in three different high pressure (HP) units (1, 2 and 3) recording contrasting pressure (P)–temperature (T) conditions. Eclogites from HP-unit 1 experienced peak metamorphic conditions in the coesite stability field at about 33 kbar/850 °C. Commonly, these eclogites from HP-unit 1 are all very...
Article
Exsolved and coarsened lamellae in Fe-free clinopyroxene are studied experimentally in the range of 1100o to 1300oC. These data provide a reliable basis for the estimation of chondrule cooling rates derived from the microstructure of chondrule minerals.
Article
The reaction of 5 to 10 mm sized labradorite feldspar single crystals (composition An51) with H2O-HCl solutions at 200°C and a pressure of 1.6 Mbar for 5 hours to five days produced solid reaction layers of amorphous silica around a core of labradorite or a solid residual of completely amorphous silica. The dissolution process was non-stoichiometri...
Article
Attempts are made to quantify cooling rates of chondrules from the microstructure of clinopyroxene and Ca-rich plagioclase. Pigeonite/diopside exsolution lamellae on (001) are frequently observed in Allende granular olivine pyroxene chondrules. Cooling rates of 2–10°C/h are obtained for the observed wavelengths between 25 and 33 nm from isothermal...
Article
The microstructures of minerals of three granular olivine-pyroxene chondrules from the Allende carbonaceous chondrite have been studied by methods of transmission electron microscopy, including electron diffraction and energy dispersive X-ray microanalysis. The main issue is to deduce the thermal and deformational history of the chondrules. The cho...
Article
Full-text available
Mineralogy and texture of chondrules have been reproduced experimentally and it was demonstrated that the abundance of heterogeneous nuclei is an important factor controlling chondrule textures. Cooling rates of chondrules were estimated from the zoning patterns of olivine. Low cooling rates (less than 100 C/h) yielded chemically homogeneous olivin...
Article
The prognosis of intraocular foreign bodies consisting of lead remains controversial. While experiments have shown that infected lead becomes sterile when fired from rifles, both the total absence as well as presence of severe inflammation have been observed following perforating injuries with lead. Furthermore, alterations of the ERG have been des...
Article
Methods of transmission electron microscopy (TEM), including imaging, electron diffraction, and energy dispersive X-ray microanalysis, have been used to study the microstructure of clinopyroxenes from the Shergotty meteorite. The aim was to contribute to the knowledge of the thermal and deformational history of this meteorite which stems probably f...
Article
Hintergrund: Die Prognose von intraokularen Bleifremdkörpern ist umstritten. Obwohl experimentelle Untersuchungen demonstrierten, dass selbst infizierte Bleiprojektile durch Abschuß keimfrei werden, wurde sowohl über das reizfreie Einheilen als auch über entzündlich toxische Reaktionen auf intraokulare Bleifremdkörper berichtet. Darüber hinaus kann...
Article
The microstructure, microchemistry and electronic structure of the electron-doped superconductor Nd2 − xCexCuO4 − δ were studied as functions of cerium and oxygen concentration by means of X-ray diffraction and transmission electron microscopy including selected area electron diffraction, energy dispersive X-ray microanalysis and electron energy lo...
Article
Based on the available literature, the state of the art of different analytical approaches for the characterization of cermets is discussed according to their information content as well as their applicability for routine analysis.Different wet chemical procedures for the dissolution of the binder phase were investigated and SEM and EDX were used t...
Article
Sintered AIN specimens were deformed by Vickers hardness (HV) indentations. Compared with Al2O3 the HV hardness values indicate a much higher plasticity of AIN at room temperature, but above 600°C a higher ductility for Al2O3. Deformed AIN specimens were examined by transmission electron microscopy. Basal and prismatic glide with the slip systems (...
Article
Full-text available
Stacking faults of the type 1/4 〈110〉 {110} have been observed in magnetic crystals of a chondrule from the meteorite Allende. A stacking fault assemblage of all six possible orientations of the faults has been analysed in detail. The displacement vector 1/4 〈110〉 is always perpendicular to the corresponding fault plane {110}. It is shown that othe...
Article
A series of YBa2Cu3O7−x thin films was deposited on (100) SrTiO3 substrates in order to study the electrical properties of the films for different oxygen contents of the material. Combined electron diffraction and electron energy loss analyses yield information on the crystal and the electronic structure of YBa2Cu3O7−x withhigh lateral resolution....
Article
We have measured the Cu 1s and 2p near-edge x-ray-absorption, electron-energy-loss, and resonant-photoemission spectra of superconducting n-type doped Nd2-xCexCuO4. The 1s x-ray-absorption spectra appear consistent with two possibilities: (1) that Ce causes a decrease in the Cu valence; and (2) that Ce causes a shift in the Cu 1s position. However,...
Article
Transmission electron microscopic methods including electron diffraction and energy dispersive X-ray microanalysis were used in order to study superstructure formation in superconducting and nonsuperconducting Nd2−xCexCuO4−δ ceramic samples. Two different modifications and structural transformations were induced by heating the samples “in situ” in...
Article
We have measured the Cu 1{ital s} and 2{ital p} near-edge x-ray-absorption, electron-energy-loss, and resonant-photoemission spectra of superconducting {ital n}-type doped Nd{sub 2-{ital x}}Ce{sub {ital x}}CuOâ. The 1{ital s} x-ray-absorption spectra appear consistent with two possibilities: (1) that Ce causes a decrease in the Cu valence; and (2)...
Article
A cordierite crystal about 3 mm in size, which occurred in a small metapelitic xenolith from the Bellerberg volcano, Eifel, was studied by methods of transmission electron microscopy (TEM). TEM showed that the grain was subdivided into regions of different types of microstructures. These regions are from a few μm up to 0.1 mm in size. They range fr...
Article
Pigeonite, orthopyroxene and clinoamphibole exsolution lamellae in slowly cooled augite are studied by conventional and high resolution transmission electron microscopy. The pigeonite-augite interface orientations and relative lattice rotations are used as geothermometers. Exsolution temperature estimates are about 900°C and ≤500°C for pigeonite ge...
Article
The microstructure and crystallographic preferred orientation (here referred to as texture) in lherzolites of the Balmuccia massif have been investigated in order to unravel the thermomechanical history of this massif. Two deformation events may be recognized in the microstructure. In olivine the first deformation led to a coarse-grained dynamic re...
Article
This paper presents new data on trace elements in fayalite-rich rims, veins, halos, and matrix olivines in the Allende meteorite. On the basis of new evidence, it is argued that the fayalitic rims were formed by condensation from a gas, and not by thermal equilibration of forsterite with FeO-rich metal or FeO-rich olivine in the interior of a paren...
Chapter
Pigeonite and clinoamphibole exsolution lamellae in augite have been studied by conventional and high resolution transmission electron microscopy. The pigeonite lamellae lie close to the (100) and (001) planes of augite with a deviation of about 15°. With increasing width of the lamellae the interphase boundary becomes semicoherent. The nucleation...
Article
Two types of antiphase domains (APD) may occur in anorthite at room T, which may be imaged and identified by TEM: b-APDs with the displacement vector 1/2(110) and c-APDs with the displacement vector 1/2(111). The APDs are translational variants and arise as a consequence of the phase transitions C1-I1 and I1-P1, respectively; their displacement vec...
Article
Transmission electron microscopic study of synthetic CaAl2Ge2O8-feldspar revealed two types of antiphase domains: type "b"-antiphase domains with the displacement vector 1/2 [110] and type "c"-antiphase domains with the displacement vector 1/2 [111]. The "b"-domains were on the order of 0.1 μm in size, while the "c"-domains displayed wall to wall d...
Article
Mineral constituents of chondrules and matrices of the unequilibrated ordinary chondrites Chainpur (LL3), Mezö-Madaras (L3) and Tieschitz (H3) have been studied by means of transmission electron microscopy and attached energy-dispersive X-ray microanalysis. As is typical for petrologic type 3, clinopyroxene is the dominant pyroxene, orthopyroxene i...
Article
Shock recovery experiments on melilite samples in the pressure range from 11 to 50.5 GPa have been performed in order to examine the effects of shock waves on this material. The shocked samples were subsequently studied in the transmission electron microscope. All samples displayed the shock-induced amorphous areas, known as diaplectic glass. The a...
Article
Antiphase domains with displacement vector 1/2(110) and 1/2(111) may occur in anorthite. From the displacement vectors the subsolidus phase transitions C1 rt arrow I1 rt arrow P1 may be deduced, involving losses of translational symmetry. Anorthites experimentally crystallized from CaAl2Si2O8 glass and those grown from the melt of the system CaMgSi...
Article
Shock recovery experiments on synthetic MgAl2O4-spinel samples in the pressure range 25.5 to 50.5 GPa have been performed in order to examine the effects of shock waves on this material. The shocked samples were subsequently studied in the transmission electron microscope. All samples showed shock-induced dislocations with the Burgers vector 1/2 11...
Article
Kulkeite occurs as platy, colorless, porphyroblastic, single crystals up to 2 mm in size in a low-grade dolomite rock associated with a Triassic meta-evaporite series at Derrag, Tell Atlas, Algeria, It is associated with sodian aluminian talc, unusual chlorite polytypes, and both K and Na phlogopite. Kulkeite is optically biaxial, negative, n x=1.5...
Article
Phase transitions and associated domains of meteoritic troilite (FeS) have been studied by means of transmission electron microscopy (TEM). Three polymorphs have been found, two of which can be described by superstructures of the NiAs-type structure (A, C subcell). The P \(\overline 6\) 2c (√3A, 2C) polymorph, stable at room temperature, displays a...
Article
High-temperature plagioclases NaAlSi3O8(Ab)-CaAl2Si2O8(An) have been prepared by dry devitrification of glasses. X-ray powder photographs were taken to follow the time-temperature dependence of indicators of structural state and to determine the lattice parameters of the plagioclases as well as their K-exchanged equivalents. Transmission electron m...
Article
The principal mineral component in the matrix of the Cochabamba carbonaceous chondrite is a phyllosilicate, which is identified as cronstedtite mainly on the basis of its chemical composition. Its approximate idealized formula is given by M6 Fe 0.7 3+ Al0.5Si2.7O10 (OH)8 with M=Fe2+, Fe3+, and Mg in somewhat variable amounts. TEM studies reveal the...
Article
Sr-feldspar: The electron diffraction data obtained agree with the space group 12/c determined by X-ray methods. The antiphase domains present are considered to originate from a subsolidus phase transition due to ordering of Al and Si. Polysynthetic twins of the Carlsbad law have been found. Sr-hexacelsian: Three polymorphs with the probable space...
Article
A unique clinopyroxene (En19Fs78Wo3), clinoeulite, space group P21/c, \text(Fe\text1\text.48 \textMg\text0\text.37 \textMn\text0\text.08\text2 + \textCa\text0\text.05 \textAl\text0\text.01 \text)\text1\text.99 \text [Si\text2\text.01 \textO6],{\text{(Fe}}_{{\text{1}}{\text{.48}}} {\text{Mg}}_{{\text{0}}{\text{.37}}} {\text{Mn}}_{{\text{0}}{\text{...
Article
Full-text available
Phase transitions and associated domains of BaAl2Si2O8-hexacelsian were studied by means of transmission electron microscopy combined with energy-dispersive X-ray microanalysis. Two polymorphs were found: a hexagonal with space group P63/mcm and a pseudohexagonal orthorhombic one with space group Immm. P63/mcm-hexacelsian displays antiphase domains...
Article
The isotypic minerals pectolite and serandite have been studied by transmission electron microscopic methods in order to examine if their structural similarities to wollastonite are reflected in their polytypic behavior. Pectolite and serandite exhibit like wollastonite stacking faults parallel to (100) with a displacement vector of ½b. A polytype...
Chapter
The polymorphs of BaAl2Si2O8 known so far are celsian, paracelsian and hexacelsian. Celsian is a monoclinic feldspar mineral with a 14 Å c-axis and a body-centered lattice (Newnham and Megaw, 1960). Paracelsian, which also occurs as a mineral, has a framework structure similar to the feldspar structure (Smith, 1953; Bakakin and Belov, 1961; Craig e...
Article
The irreversible changes occurring in minerals as a result of shock loading were examined. These effects were analyzed in the pressure range from 100 to 600 mbar. Tests carried out were: inclusion of the sample in a block of steel, shock wave generation by detonation of an explosive charge, and determination of the shock wave pressure in the sample...
Article
Uniaxial compression at 800 degrees C and 5 kilobars confining pressure of a specimen cored from a single crystal of orthoenstatite [(Mg,Fe)SiO(3)] produced fine lamellae 100 to 1000 angstroms thick of untwinned clinoenstatite. The two phases are joined along (100) planes and have b and c axes in common. The orientation of the clinoenstatite a axis...
Article
As part of an electron microscopic study of plagioclase, displacement vectors for b- and c-domains have been determined from contrast experiments and calculations. In lunar anorthite from breccia 15459 (An 94.9), b-domains could be imaged in dark field with b-reflections and c-domains with c-reflections. The vector corresponding to these contrast c...
Article
Full-text available
The paper is a compilation of data on antiphase domains in lunar plagioclase. New observations and reports in the literature are tabulated and discussed. In the pattern which emerges (but is still very incomplete), it appears that b-domains, which except for the An 82 bytownite from the Stillwater complex have only been observed in lunar feldspars,...
Article
Mineralogical properties of calcic plagioclase have been analyzed using U-stage, microprobe, X-ray precession cameras, and a 650-kV electron microscope. The orientation of the optical indicatrix in lunar and eucrite anorthites is described with Euler angles. All crystals, except one, show strong b- and diffuse c-reflections in precession photograph...
Article
Variations of structure and optical properties in anorthites (An 93–97%) of different origin are analyzed with the petrographic microscope, U-stage methods, X-ray single crystal analysis and high voltage electron microscopy. No significant variation has been found in the orientation of the indicatrix and of the lattice constants. But c-type reflect...
Article
Full-text available
Apollo 11 lunar soil and breccia shock metamorphism, examining plastic deformation structures in plagioclase, pyroxene and olivine
Article
Indications of shock metamorphism produced by pressures up to the megabar region have been observed in the fine material and the breccias, but very rarely in the coarser fragments of crystalline rocks. These indications are deformation structures in plagioclase and pyroxene, diaplectic plagioclase glasses, and glasses formed by shock-induced meltin...
Article
Full-text available
The rheological behaviour of eclogite is dominated by the deformational properties of omphacite which therefore are most important for the geodynamic processes of subduction and exhumation of oceanic and continental crust. The deformation mechanisms activated are obviously not the same in eclogites from different geological areas as shown by severa...
Article
Shock wave compression experiments in the peak pressure range ⋍50 to 430 kb were performed on single olivine crystals and on specimens drilled from an olivine nodule. All shocked specimens display planar deformation structures parallel to {100}, {010}, {001}, {130}, and {hkl} (bipyramids). The planar structures parallel to {130} and {hkl} are appar...
Article
PETROGRAPHIC studies of rocks from meteorite craters and experimental work have shown that shock waves induce characteristic deformation and transformation phenomena in quartz and feldspar. To obtain information about shock effects in mafic minerals, we have started experiments on olivine (Mg,Fe)2SiO4, and report here our first results.

Network

Cited By