Growth of R-123 Phase Single Crystal Whiskers

Single-crystal whiskers of R1Ba2Cu3Ox (R-123, R= La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu) phase have been successfully grown by the Te- and Ca-doping method. The whiskers were grown from precursor pellets at just below their partial melting (peritectic) temperatures. The nominal composition of the R-123 whiskers is R1+uBa2+vCawCu3Ox (u+v+w=0, w>0) with R and/or Ba sites being substituted by Ca. However, the amount of Te was less than the analytical limit. The critical temperatures of the R-123 whiskers were around 80 K, and among these whiskers those with larger R ionic radii such as Dy, Gd, Eu and Sm require post-annealing in an oxygen atmosphere.Comment: R1Ba2Cu3O7-d, whisker, R ionic radius, crystal growth, Ca including R-123 phase, critical temperature, composition. To be published in Jpn. J. Appl. Phy

Diagnosis and Surgical Management of Foramen Magnum Meningioma

Two cases of foramen magnum meningioma were successfully treated at early stage. The magnetic resonance imaging (MRI) played an important role for accurate diagnosis. The tumors were microsurgically removed and the patuents returned to socity in full capacity. The foramen magnum meningioma is rare, and potentially curable. The recognition of this entity is important for neurologists, orthopodists and neurosurgenos in the differential diagnosis of the craniocervical problems