Research Papers in Physics and Astronomy

 

Date of this Version

2002

Comments

Published in Microsc. Microanal. 8 (Suppl. 2), 2002. Copyright © Microscopy Society of America 2002. Used by permission.

Abstract

In current extremely high density recording media design, the signal to noise ratio SNR is related to the number of magnetic grains N in a recording bit by
SNR = 10 logl0 N .................................... (1)
In earlier studies we have found that a metallurgical grain can act as a magnetic grain when grains are magnetically decoupled by a non-magnetic phase [1,2]. Alternatively, several metallurgical grains can be exchange-coupled together when they are small [3]. An ideal morphology is one in which the non-magnetic atoms are segregated at the grain boundaries forming the non-magnetic phase while keeping the grains closely packed.