The specific heat, C, of single crystals of CuGe1-xSixO3 (x = 0, 0.005, 0.008, 0.01, 0.015, 0.02, 0.027, 0.05) under magnetic field up to 15 T were measured and their magnetic phase diagrams were determined. The compounds with x ≤ 0.015 exhibit two transitions at TSP and TN in low magnetic field. An upturn of C/T for x = 0.005 and 0.008 below ∼ 3 K originating from the AF ordering at lower temperatures is suppressed by magnetic field as in the case for x = 0.01. However, the existence of M′ phase above ∼ 10 T which was observed for x = 0.01 was not recognized for x = 0.005 and 0.008, which suggests the existence of a critical x value for the appearance of M′ phase.
- Impurity effect
- Magnetic phase diagram
- Spin-Peierls state
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering