Mössbauer study of ceramic finds from the early Phoenician palace in Kāmid El-Lōz,Lebanon

A Mössbauer typology of 120 early phoenician ceramic sherds from Kāmid El-Lōz, Lebanon, is proposed. It is found to agree well with other classifications by means of neutron activation analysis and thin section microscopy. Two ancient calcium rich clays and one recent calcium poor clay from the same region were fired in the laboratory in oxidizing and reducing atmospheres at temperatures increasing stepwise from 50 °C to 1200°C, with Mössbauer spectra taken at room temperature and occasionally at 4.2 K. These model experiments were undertaken with the aim to reconstruct the firing techniques of the early phoenician potters. The firing temperature of the locally made pottery appears to have been low.     

Evidence for a new,stress-induced phase transition in KMnF3

A new, stress-induced phase of KMnF₃ is found in emission, absorption and a.c.-susceptibility measurements. The phase transition is of first order and it occurs under uniaxial stress parallel to the [100] and to the [110] pseudocubic axes at 20.1 and 27 kp/mm² at 1.7 K. The experimental results are explained by a change in the amount of the tetragonal distortion in the new, stress-induced phase.     

Formative ceramics from the Andes and their production: A Mössbauer study

The potential of Mössbauer spectroscopy in the reconstruction of production techniques of early ceramics is demonstrated by the results of a study of a Formative kiln site at the Archaeological Park at Batán Grande, Perú, and of ceramics from the nearby settlement of Huaca Chólope.     

Far-infrared Fabry Perot filter of high transmission with high-Tc superconductor reflectors

We report on a far-infrared Fabry Perot filter with high-T _c superconductor reflectors that has a high peak-transmission. The filter consists of two plane parallel MgO plates, with the adjacent surfaces coated with YBa₂Cu₃O₇-gd thin films. The resonance frequencies are mainly determined by the distance between the films. We present data for a filter that has for the first order resonance at a frequency of 80 cm^–1a quality factor of 55 and a peak-transmissivity of 0.16. The shape of the transmission curve is determined by standing waves between the films and within the plates.     

Beitrag zur Anwendung der Infrarotspektroskopie für Untersuchungen von Farberden kulturhistorischer Objekte im Vergleich mit rezenten europäischen Lagerstätten

Various iron oxide pigments have been analysed by means of infra-red spectroscopy and 10 characteristic minerals have been found, which are utilized for distinguishing and classifying the pigments. In case of paintings certain difficulties arise because of the possible admixture of other pigments and fillers.     

Terphenyl cyclooctatetraenyl compounds of samarium

The syntheses and molecular structures of a number of terphenyl-based compounds of the lanthanide element samarium are reported. Reaction of 2 equiv of DppLi (Dpp = 2,6-diphenylphenyl) with 1 equiv of SmCl(3) in tetrahydrofuran at room temperature yields (Dpp)(2)SmCl(micro-Cl)Li(THF)(3) (1). The one-pot reaction of 1 equiv of K(2)COT (COT(2)(-) = cyclooctatetraenyl dianion) with 1 equiv SmCl(3) in tetrahydrofuran at room temperature followed by addition of 1 equiv of terphenyllithium salt DppLi, DmpLi (Dmp = 2,6-dimesitylphenyl), or DanipLi (Danip = 2,6-di(o-anisol)phenyl) produces DppSmCOT(micro-Cl)Li(THF)(3) (2), DmpSm(THF)COT (3), and DanipSm(THF)COT (4), respectively. In the case of the Danip-based compound 4 the order of addition of reagents can be reversed producing the same compound, however, in considerably lower yield. Compound 2 can also be prepared by reaction of 1 with 1 equiv of K(2)COT in tetrahydrofuran. The molecular structure of the bis(terphenyl) compound 1 exhibits a formally four-coordinate metal atom. The molecular structures of the terphenyl COT compounds 2-4 feature monomeric complexes which are obtained either as a lithium chloride adduct (2) or as tetrahydrofuran adducts (3, 4). In 4 the Danip ligand adopts the meso form.