Accession Number : AD0725169

Title :   Low Temperature Heat Capacity of the Metamagnet Ni(NO3)2.2H2O.

Descriptive Note : Technical rept.,

Corporate Author : CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF PHYSICS

Personal Author(s) : Polgar,L. G. ; Friedberg,S. A.

Report Date : 15 MAY 1971

Pagination or Media Count : 18

Abstract : The heat capacity C sub P of Ni(NO3)2.2H2O has been measured in the range 1.5 = or < T = or < 10K, revealing a sharp lambda-anomaly, characteristic of the transition to a magnetically ordered state, at T sub N = 4.105 plus or minus 0.005K. The magnetic contribution to C sub P has been separated from the lattice part and the temperature variation of the magnetic entropy calculated. The magnetic entropy at T sub N is found to be only 0.546R suggesting a two-dimensional character to the ordering which is compatible with the picture of this system as an antiferromagnetically coupled array of alternating sheets of ferromagnetically aligned Ni++ spins. This interpretation, however, is complicated by the effect of anisotropy on C sub P. (Author)

Descriptors :   (*ANTIFERROMAGNETISM, NICKEL COMPOUNDS), (*SPECIFIC HEAT, NICKEL COMPOUNDS), TRANSITION TEMPERATURE, NITRATES, HYDRATES, CRYOGENICS, ANISOTROPY

Subject Categories : Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE