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Title: Systematic study of the spin stiffness dependence on phosphorus alloying in the ferromagnetic semiconductor (Ga,Mn)As

We study the dependence of the spin stiffness constant on the phosphorus concentration in the ferromagnetic semiconductor (Ga,Mn)(As,P) with the aim of determining whether alloying with phosphorus is detrimental, neutral, or advantageous to the spin stiffness. Time-resolved magneto-optical experiments are carried out in thin epilayers. Laser pulses excite two perpendicular standing spin wave modes, which are exchange related. We show that the first mode is spatially uniform across the layer corresponding to a k≈0 wavevector. From the two frequencies and k-vector spacings we obtain the spin stiffness constant for different phosphorus concentrations using weak surface pinning conditions. The mode assessment is checked by comparison to the spin stiffness obtained from domain pattern analysis for samples with out-of-plane magnetization. The spin stiffness is found to exhibit little variation with phosphorus concentration in contradiction with ab-initio predictions.
Authors:
; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. CNRS, UMR7588, Institut des Nanosciences de Paris, 4 place Jussieu, 75005 Paris (France)
  2. (France)
  3. Laboratoire Matériaux Molécules et Applications, IPEST, Université de Carthage, B.P. 51, 2075 La Marsa (Tunisia)
  4. Laboratoire de Photonique et Nanostructures, CNRS, UPR 20, Route de Nozay, 91460 Marcoussis (France)
Publication Date:
OSTI Identifier:
22398860
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 14; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; ELECTROMAGNETIC PULSES; FERROMAGNETIC MATERIALS; FLEXIBILITY; LASER RADIATION; MAGNETIC SEMICONDUCTORS; MAGNETIZATION; MAGNETO-OPTICAL EFFECTS; PHOSPHORUS; SPIN; SPIN WAVES; SURFACES; TIME RESOLUTION; VARIATIONS