Polarized neutron reflectivity of dilute magnetic semiconductors

Chemical and magnetic profile of magnetic semiconductors as probed by polarized neutron reflectivity

“…The magnetization that was observed for DMS4Fe2Mn from SQUID, is therefore cannot be intrinsic to the DMS layer but, can be owed to the presence of segregated clusters. Our present results for DMS2Fe4Mn corroborate with previous measurements by TEM or SQUID on similar specimens 5,6 . This is further confirmed with the TREFF data as we find that for DMS2Fe4Mn, a clear improvement (improved by ∼0.05) is achieved when M 2 is employed as compared to M 1 .…”

“…5 For an annealing temperature T A = 300 C a homogeneous alloy is observed by XRR measurements. 6 Magnetization measurements by a superconducting quantum interference device (SQUID) and magnetotransport measurements reveal ferromagnetic ordering, but show two different T C s at 205 K and above 300 K for "DMS2Fe4Mn", which we relate to two magnetic phases.…”

“…Magnetization measurements by a superconducting quantum interference device (SQUID) and magnetotransport measurements reveal FM ordering, but show two different T C s at 205 K and above 300 K for 'DMS2Fe4Mn', which we relate to two magnetic phases. Interestingly, 'DMS4Fe2Mn' does not show the high-T C phase and appears in the transmission electron microscope (TEM) picture to be fairly homogeneous compared with the other samples [5,6]. TEM indeed showed the formation of precipitates depending upon the content of the magnetic species [5] for the two compositions.…”

“…The samples are grown by MBE, details of which have been given elsewhere [5]. For an annealing temperature T A = 300 • C a homogeneous alloy is observed by XRR measurements [6].…”

Invited Article: Polarization “Down Under”: The polarized time-of-flight neutron reflectometer PLATYPUS

“…7 The technique also has been utilized to study buried magnetic structures in exchange bias systems [8][9][10][11][12] and non-metallic systems, such as magnetic oxide thin films and semiconductors. [13][14][15][16][17] More recently, PNR has also been used as the source of additional scattering contrast in characterization of soft condensed matter solid/liquid interfaces with a magnetic underlayer. [18][19][20][21] For a more comprehensive review of the PNR technique and scientific examples, we refer to recent contributions in Ref.…”