
%0 Journal Article
%A Tokunaga, M. 
%A Miura, N. 
%A Moritomo, Y. 
%T High-field Study of Layered Manganites <emph type="2">R</emph><emph tye="8">1/2</emph>Sr<emph tye="8">3/2</emph>MnO<emph tye="8">4</emph> (<emph type="2">R</emph> = La and Nd)
%J Australian Journal of Physics
%D 1999/04/28
%V 52
%N 2
%P 227-234
%K 
%R https://doi.org/10.1071/P98044
%U https://www.publish.csiro.au/paper/P98044 
%X We have studied the effects of a magnetic field on the magnetism and transport properties of the layered manganites R1/2Sr3/2MnO4 (R = La and Nd) in pulsed magnetic fields up to 40 T. The R = La crystal shows metamagnetic-like transitions above 30 T, concomitantly with a colossal magnetoresistance (CMR) effect as large as &#91;&rho;(0) - &rho;(H)&#93;/&rho;(H) &#62; 103 with a field of &#181;&ogr;H = 38 T at low temperatures. These transitions can be ascribed to the field-induced melting of the real-space ordering of the eg electrons (charge ordering). For the R = Nd crystal, a magnetic field along the c-axis enhances the two-dimensionality in the conductivity. Moreover, we observed metamagnetic-like transitions accompanied by the CMR effects at low temperatures, in spite of the absence of charge ordering. 
