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Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation fields and low coercivity at high T consistent with thick films Loops exhibit qualitative change below ~150 K, where they
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Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation.

Dec 30, 2015

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Merilyn Burke
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Page 1: Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation.

Characteristic MOKE Loops for S320

• Strong signals up to 320 K (upper limit of the measurements)• Nearly square loops at high temperatures• Low saturation fields and low coercivity at high T consistent with thick films• Loops exhibit qualitative change below ~150 K, where they show

characteristic dependence on sweep direction of the field

Page 2: Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation.

Temperature Dependence for S320

• Bulk like transition temperature

(~ 350 K)

• Broad max/plateau around 260

K suggests reorientation,

consistent with thick epitaxial

films grown on STO

• Remanent MOKE signals exhibit

dependence on field direction

below 150 K, corresponding to

the qualitative change in the

shape of the loops

• The low temperature behavior is

consistent with a change of

anisotropy and the presence of

quadratic MOKE effect

Arrows indicate the loops shown in previous slide

Page 3: Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation.

Temperature Dependence for S320

Page 4: Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation.

Characteristic MOKE Loops for S311

• No longitudinal MOKE signal above ~ 170 K• Nearly square loops with large coercivity below ~ 150 K• Kerr rotation signal does not show monotonic increase as temperature

decreases, whereas ellipticity and Hco counterparts do

• Behavior qualitatively different from sample 320

Page 5: Characteristic MOKE Loops for S320 Strong signals up to 320 K (upper limit of the measurements) Nearly square loops at high temperatures Low saturation.

Temperature Dependence for S311

• Significantly suppressed

transition temperature (did not

do polar MOKE to check for

perpendicular anisotropy)

• Coercivity significantly larger

than S320 (thick LSMO film

without a layer of BTO)

• Suppressed signals and

transition temperature suggest

strong influence by the

presence of BTO and possibly

low film thickness

Arrows indicate the loops shown in previous slide