Biomedical subjects

M Mekata

Publications and source records attributed to M Mekata.

12 recordsLinked to original sources

PubMed2000

Ga NMR study of the local susceptibility in Kagome-based SrCr8Ga4O19: pseudogap and paramagnetic defects

We present the first Ga(4f ) NMR study of the Cr susceptibility in the archetype of kagome-based frustrated antiferromagnets, SrCr8Ga4O19. Our major finding is that the susceptibility of the frustrated lattice goes through a maximum around 50 K. Our data also support the existence of paramagnetic "clusters" of spins, responsible for the Curie behavior observed in the macroscopic susceptibility at low T. These results set novel features for the constantly debated physics of geometrically frustrated magnets.

Journal Article↗

PubMed2000

Magnetic dilution in the geometrically frustrated SrCr(9p)Ga(12-9p)O19 and the role of local dynamics: A muon spin relaxation study

We investigate the spin dynamics of SrCr(9p)Ga(12-9p)O19 for p below and above the percolation threshold p(c) using muon spin relaxation. Our major findings are as follows: (i) At T-->0 the relaxation rate is T independent and approximately p(3), (ii) the slowing down of spin fluctuation is activated with an energy U, which is also a linear function of p(3) and lim U as p-->0 = 8 K; this energy scale could stem only from a single ion anisotropy, and (iii) the p dependence of the dynamical properties is identical below and above p(c), indicating that they are controlled by local excitation.

Journal Article↗

PubMed1996