Terahertz generation in langatate crystal by optical rectification

International audienc

Spinodal Decomposition in Lead-free Piezoelectric BaTiO3 –CaTiO3 –BaZrO3 Crystals

Polycrystals and centimeter-sized BaTiO3-based single crystals were grown by top seeded solution growth from the BaTiO3–CaTiO3–BaZrO3 system. High effective partition coefficients of Zr ranging from 15 to 6 with small Zr content have been calculated from Castaing microprobe measurements, whereas those of Ca increase slightly from 0.45 to 0.7. A spinodal decomposition mechanism is emphasized during the growth leading to the emergence of two phases with close compositions. Chemical analysis displayed periodical Zr and Ca content fluctuations within the whole boules, and Rietveld measurements highlighted two phases belonging to perovskite structures with tetragonal P4mm and orthorhombic Amm2 space groups. Samples with various calcium and zirconium contents were characterized by means of dielectric and piezoelectric measurements. Most efficient samples are indistinctly polycrystals or oriented single crystals where electromechanical performances are compositional-dependent. Polycrystalline samples and single crystals oriented along (001)pc and (110)pc displayed Curie temperatures ranging from 50 to 111 °C. Electromechanical coupling factor up to 58% and piezoelectric charge coefficient d33 = 496 pC·N–1 were obtained at room temperature. The miscibility gap between the two perovskite solid solutions as well as Ca and Zr element content variation in single crystals lower crystal piezoelectric response that remains nonetheless of the same efficiency compared to that of ceramics of the same composition

Primary Biliary Cholangitis Associated with Skin Disorders: A Case Report and Review of the Literature.

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease. It is often associated with extrahepatic autoimmune diseases. Skin disorders are sporadically reported in association with PBC. We report an unusual case of PBC associated with acquired reactive perforating dermatosis (ARPD) and present a review of the literature on skin disorders associated with PBC. Our patient presented to the dermatology department with generalized pruritus associated with nodular perforating skin lesions on the trunk, and cholestatic liver disease of unknown origin. After having established both diagnosis of ARPD and PBC, she was managed in an interdisciplinary manner, and both her skin and liver conditions improved gradually. Only one similar case is reported in the literature, in that case, the liver disease was not treated. By reviewing the literature, we found that lichen planus, vitiligo, and psoriasis are the most frequent skin disorders associated with PBC. However, there is only limited data about specific skin disorders associated with PBC. This case report of a patient with PBC associated with ARPD underlines the importance of interdisciplinary management of patients with rare liver diseases combined with rare skin disorders. The present review of the literature shows that probably, immune-mediated skin conditions are not more frequent in PBC patients than in the general population. However, the available data are scant; there is a need for high-quality data on skin conditions associated with PBC