| Autor: |
Yosuke Shindo, Akira Oosawa, Hidekazu Tanaka |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
Progress of Theoretical Physics Supplement. 159:189-194 |
| ISSN: |
0375-9687 |
| Popis: |
The effect of exchange randomness on the ground state and the field-induced magnetic ordering was investigated through specific heat and magnetization measurements in Tl 1-x K x CuCl 3 with x < 0.22. The isostructural parent compounds TlCuCl 3 and KCuCl 3 are coupled spin dimer systems with a gapped singlet ground state and their field-induced antiferromagnetic ordering is described by the Bose condensation of spin triplets. Due to exchange randomness, the low-field singlet ground state turns into the magnetic state with finite susceptibility. However, the gap for the triplet excitation still remains. Well-defined field-induced phase transitions were observed in Tl 1-x K x CuCl 3 . The relation between transition field H N (T) and temperature is represented by the power law H N (T)- H c ∞ T Φ . Systematic decrease of the critical exponent Φ with x is observed. These properties are discussed in connection with Bose gas in the presence of random potential. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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