Magnetic properties of the Biâ Srâ CaCuâ Oâ single crystal

The Bi2Sr2CaCu20g single crystal with a superconducting transition temperature equal to 90 ± 2 K was prepared. The irreversibility line of the single crystal for a mgnetic field direction along the c-axis and T* in the ab-plane was determined. The reduced temperature (l - T ) is proportional to H 1.1 for fields below 004 T and proportional to HO.09 for fields above 0.4 T. The zero temperature upper critical field Hc2(0) and coherence length ~ (0) were determined from the magnetization meaurements to be H-lC2=35.9T , H//C2=31.2T, ~c(0)=35.0 A, and ~ab(0)=32.5A,and from the magnetoresistance measurements to be H-lc2 = 134.6T , H//C2=55.5T '~c(0)=38.1 A, and ~ab(0)=2404 A for both directions of the applied magnetic field. The results obtained for Hc2(0) and ~(O) are not reliable due to the rounding that the single crystal exhibits in the magnetization and magnetoresistance curves. The magnetization relaxation of the single crystal was investigated, and was found to be logarithmic in time, and the relaxation rate increases with temperature up to 50 -60 K, then decreases at higher temperatures.

Letter - E.C. Schmon to Arthur A. Schmon, 2 January 1918

The letter describes a conversation Eleanore Celeste had with her mother as she studied the Prussian-Danish War of 1864. Her mother was in Denmark at the time and elaborated on her studies. Eleanore Celeste's grandfather "held a high position in the Danish court". The family had kept an album of photographs that included pictures of Frederick VII, Christian IX etc. The pictures had been given to him by the Royal family. The next part of the letter talks about Arthur possibly returning to the United States at the end of the year. She also mentions that Arthur had sent a letter to his mother about either returning to the United States or possibly getting assigned to troops and she became upset. Eleanore Celeste writes that she tried to console Arthur's mother, but she "began picturing you at the front, in the midst of the danger". This letter is labelled 38th.