{"id":6089,"date":"2026-10-19T09:48:27","date_gmt":"2026-10-19T09:48:27","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-edlisfraedi-movaffaq-kateb\/"},"modified":"2026-10-19T09:48:27","modified_gmt":"2026-10-19T09:48:27","slug":"doktorsvorn-i-edlisfraedi-movaffaq-kateb","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-edlisfraedi-movaffaq-kateb\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed e\u00f0lisfr\u00e6\u00f0i – Movaffaq Kateb"},"content":{"rendered":"
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Doktorsefni:<\/strong>\u00a0Movaffaq Kateb<\/p>\n

Heiti ritger\u00f0ar:<\/strong>\u00a0Sp\u00f6nu\u00f0 ein\u00e1sa segul\u00e1ttun \u00ed einkrist\u00f6llu\u00f0u, fj\u00f6lkrist\u00f6llu\u00f0u og ofurgrindum \u00far permalloy \/ Induced uniaxial magnetic anisotropy in polycrystalline, single crystal and superlattices of permalloy<\/p>\n

Andm\u00e6lendur:<\/strong>
<\/strong>Dr. Sigur\u00f0ur Ingi Erlingsson, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Reykjav\u00edk.
Dr. Victor Kuncser, yfirma\u00f0ur ranns\u00f3knastofu \u00ed seglun og ofurlei\u00f0ni, \u00dej\u00f3\u00f0arstofnun \u00ed efnise\u00f0lisfr\u00e6\u00f0i, B\u00fakarest \u00ed R\u00famen\u00edu.<\/p>\n

Lei\u00f0beinandi:<\/strong>\u00a0Dr. Snorri \u00deorgeir Ingvarsson, pr\u00f3fessor vi\u00f0 Raunv\u00edsindadeild.<\/p>\n

Einnig \u00ed doktorsnefnd:<\/strong> Dr. J\u00f3n T\u00f3mas Gu\u00f0mundsson, pr\u00f3fessor vi\u00f0 Raunv\u00edsindadeild.
Dr. Fri\u00f0rik Magnus, v\u00edsindama\u00f0ur vi\u00f0 Raunv\u00edsindastofnun H\u00e1sk\u00f3lans.<\/p>\n

Doktorsv\u00f6rn st\u00fdrir:<\/strong>\u00a0Dr. Oddur Ing\u00f3lfsson, pr\u00f3fessor og deildarforseti Raunv\u00edsindadeildar.<\/p>\n

\u00c1grip<\/strong><\/p>\n

Permalloy Ni80Fe20 samsetning (Py) er vel \u00feekktur j\u00e1rnsegull, nota\u00f0ur \u00ed anisotropic magnetoresistance og planar Hall effect skynjara \u00e1samt \u00fev\u00ed a\u00f0 vera n\u00fdttur \u00ed leshausa har\u00f0ra diska \u00ed t\u00f6lvum og \u00ed segulminni. \u00deessar hagn\u00fdtingar rei\u00f0a sig \u00e1 ein\u00e1sa segul\u00e1ttun \u00ed permalloy \u00feunnh\u00fa\u00f0um. \u00ddmsar a\u00f0fer\u00f0ir hafa veri\u00f0 \u00fer\u00f3a\u00f0ar til \u00feess a\u00f0 n\u00e1 ein\u00e1sa segul\u00e1ttun \u00ed efninu, svo sem a\u00f0 setja \u00e1 segulsvi\u00f0 vi\u00f0 b\u00f6kun eftir r\u00e6ktun, \u00e1 me\u00f0an \u00e1 r\u00e6ktun stendur, e\u00f0a vi\u00f0 j\u00f3na\u00e1geislun. Einnig me\u00f0 r\u00e6ktun undir hv\u00f6ssu horni og, \u00ed s\u00ed\u00f0asta lagi, aflfr\u00e6\u00f0ileg bj\u00f6gun. \u00c1 me\u00f0al \u00feessara a\u00f0fer\u00f0a hefur mest veri\u00f0 beitt r\u00e6ktun undir hv\u00f6ssu horni, en eitt r\u00e6ktunart\u00e6ki\u00f0 er einmitt \u00feannig hanna\u00f0 a\u00f0 r\u00e6ktun fer \u00f6ll fram undir hv\u00f6ssu horni.
\u00cd fyrsta hluta \u00feessa verkefnis voru borin saman \u00e1hrif r\u00e6ktunar undir hv\u00f6ssu horni og beitingu segulsvi\u00f0s \u00e1 sp\u00f6nun ein\u00e1sa segul\u00e1ttunar og s\u00fdnt a\u00f0 \u00ed samkeppni \u00feeirra \u00e1 milli haf\u00f0i fyrri a\u00f0fer\u00f0in betur (grein I). Einnig kom \u00ed lj\u00f3s a\u00f0 r\u00e6ktun undir hv\u00f6ssu horni veldur mj\u00f6g vel skilgreindri ein\u00e1sa segul\u00e1ttun, jafnvel \u00e1 brei\u00f0u svi\u00f0i r\u00e6ktunar\u00fer\u00fdstings (grein II). \u00dear sem sp\u00e6ttar j\u00f3nir g\u00e6tu skondra\u00f0 af undirlaginu vi\u00f0 h\u00e1an r\u00e6ktunar\u00fer\u00fdsting, \u00ed sta\u00f0 \u00feess a\u00f0 festast, \u00fe\u00e1 n\u00fdtum vi\u00f0 h\u00e1aflsp\u00falsa\u00f0a segulsp\u00e6tun (HiPIMS) til \u00feess a\u00f0 auka orku \u00feeirra og vi\u00f0halda \u00feannig h\u00e1um massa\u00fe\u00e9ttleika og mj\u00fakri segulheg\u00f0un Py h\u00fa\u00f0anna. \u00de\u00e1 er s\u00fdnt hvernig mj\u00f6g g\u00f3\u00f0ri ein\u00e1sa segul\u00e1ttun var n\u00e1\u00f0 \u00ed r\u00f6\u00f0 Py-s\u00fdna af mismunandi \u00feykkt. \u00dea\u00f0 var \u00e1n nokkurar sj\u00e1lfsk\u00fdlingar e\u00f0a hallandi frumeindauppr\u00f6\u00f0unar, hvort tveggja sk\u00fdringar sem nota\u00f0ar hafa veri\u00f0 fyrir uppruna ein\u00e1sa segul\u00e1ttunar (grein III). Hvorug \u00feeirra getur hins vegar veri\u00f0 \u00e1st\u00e6\u00f0a segul\u00e1ttunar \u00ed okkar Py h\u00fa\u00f0um. \u00cd n\u00e6sta fasa verkefnisins voru \u00fev\u00ed r\u00e6kta\u00f0ar einkristalla\u00f0ar Py h\u00fa\u00f0ir \u00e1 (001) MgO, undir hv\u00f6ssu horni og bornar saman dc segulsp\u00e6tun (dcMS) og HiPIMS (grein IV). \u00c1 grundvelli r\u00f6ntgenm\u00e6linga (XRD) og rafvi\u00f0n\u00e1msm\u00e6linga getum vi\u00f0 sagt a\u00f0 einkristalla\u00f0ar h\u00fa\u00f0ir r\u00e6kta\u00f0ar me\u00f0 dcMS lei\u00f0i til reglulegrar kristalbyggingar me\u00f0 L12 Ni3Fe ofurgrind en mikill r\u00e6ktunarhra\u00f0i \u00ed HiPIMS (meira en 50-faldur dcMS r\u00e6ktunarhra\u00f0i me\u00f0an \u00e1 p\u00falsi stendur) gefur \u00f3reglulegri kristalbyggingu. \u00dea\u00f0 kom \u00e1 \u00f3vart a\u00f0 einkristalla\u00f0ar h\u00fa\u00f0ir r\u00e6kta\u00f0ar me\u00f0 HiPIMS h\u00f6f\u00f0u ein\u00e1sa segul\u00e1ttun \u00ed \u27e8001\u27e9 stefnu. Hins vegar leiddi reglulega kristalbyggingin sem kom me\u00f0 dcMS r\u00e6ktun til tv\u00ed\u00e1sa segul\u00e1ttunar \u00ed \u27e8011\u27e9 stefnur, sem r\u00edmar vi\u00f0 a\u00f0 segul\u00e1ttun \u00ed bolefninu er \u00ed \u27e8111\u27e9 stefnur, en er \u00fevingu\u00f0 ni\u00f0ur \u00ed plani\u00f0 af afsegulm\u00f6gnunar\u00fe\u00e6ttinum vegna l\u00f6gunar \u00feunnh\u00fa\u00f0arinnar. Vert er a\u00f0 nefna a\u00f0 hvorki segulsvi\u00f0 \u00ed r\u00e6ktun n\u00e9 b\u00f6kun a\u00f0 lokinni r\u00e6ktun dug\u00f0u til a\u00f0 spana ein\u00e1sa segul\u00e1ttun \u00ed \u27e8001\u27e9 stefnu. \u00dea\u00f0 kann a\u00f0 stafa me\u00f0al annars af \u00fev\u00ed a\u00f0 vi\u00f0 r\u00e6ktun einkristalla er nota\u00f0ur mj\u00f6g l\u00e1gur r\u00e6ktunarhra\u00f0i. \u00dev\u00ed ver\u00f0ur ekki n\u00e6g \u00f3regla \u00ed byggingunni til \u00feess a\u00f0 valda ein\u00e1sa segul\u00e1ttun. S\u00fdnt var s\u00ed\u00f0ar a\u00f0 jafnvel \u00fe\u00f3tt mj\u00f6g erfitt s\u00e9 a\u00f0 nema \u00f3reglu \u00ed frumeindar\u00f6\u00f0un me\u00f0 XRD \u00ed fj\u00f6lkrist\u00f6llu\u00f0um h\u00fa\u00f0um m\u00e1 nota rafvi\u00f0n\u00e1msm\u00e6lingar til \u00feess a\u00f0 segja eitthva\u00f0 til um uppruna ein\u00e1sa segul\u00e1ttunar (grein V). Vi\u00f0 s\u00fdndum a\u00f0 e\u00f0lisvi\u00f0n\u00e1m h\u00fa\u00f0ar sem var r\u00e6ktu\u00f0 \u00ed segulsvi\u00f0i er \u00ed l\u00e1gmarki \u00ed stefnu har\u00f0a segul\u00e1ssins en \u00ed h\u00e1marki \u00ed stefnu au\u00f0velda segul\u00e1ssins. Vi\u00f0 f\u00e6rum r\u00f6k fyrir \u00feessu me\u00f0 r\u00f6\u00f0un frumeindanna Ni og Fe \u00ed stefnu au\u00f0velda segul\u00e1ss h\u00fa\u00f0arinnar.
Til \u00feess a\u00f0 rannsaka \u00e1hrif yfirbor\u00f0s e\u00f0a yfirbor\u00f0s\u00e1ttun \u00fatbjuggum vi\u00f0 margl\u00f6g, sem innihalda Py, me\u00f0 dcMS og HiPIMS. Vi\u00f0 s\u00fdndum a\u00f0 \u00fea\u00f0 er h\u00e6gt a\u00f0 f\u00e1 mj\u00f6g sk\u00f6rp, vel skilgreind, skil me\u00f0 HiPIMS a\u00f0fer\u00f0. \u00deessu fylgir hins vegar t\u00f6luver\u00f0 bj\u00f6gun efnisins \u00ed tilfellinu Py\/Pt sem eykur COERCIVITY og eykur \u00e1 segulheldni eftir erfi\u00f0a segul\u00e1snum. Ef nota\u00f0 er Cu e\u00f0a CuPt \u00ed sta\u00f0 Pt f\u00e6st vel skilgreind ein\u00e1sa segul\u00e1ttun.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Movaffaq lauk n\u00e1mi \u00ed efnisfr\u00e6\u00f0i fr\u00e1 Amirkabir University of Technology \u00ed Teheran \u00ed \u00cdran \u00fear sem hann f\u00e9kkst vi\u00f0 l\u00edkanger\u00f0 og hermireikninga \u00e1 e\u00f0lisfr\u00e6\u00f0ilegum eiginleikum nan\u00f3kerfa. Hann lauk meistaran\u00e1mi \u00ed nan\u00f3verkfr\u00e6\u00f0i fr\u00e1 Tarbiat Modares University \u00ed Teheran og var me\u00f0limur \u00ed sterkum ranns\u00f3knah\u00f3pi \u00e1 svi\u00f0i nan\u00f3t\u00e6kni.<\/p>\n

Movaffaq er kv\u00e6ntur Sahar Safarian og eiga \u00feau \u00ferj\u00e1 syni: Amirhossein, Taha og Yasin.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1837,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-12-12T13:30:00+00:00","_phd_date_end":"2019-12-12T15:30:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0arsalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Sp\u00f6nu\u00f0 ein\u00e1sa segul\u00e1ttun \u00ed einkrist\u00f6llu\u00f0u, fj\u00f6lkrist\u00f6llu\u00f0u og ofurgrindum \u00far permalloy \/ Induced uniaxial magnetic anisotropy in polycrystalline, single crystal and superlattices of permalloy","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_edlisfraedi_movaffaq_kateb","_phd_source_node_id":"326221","_phd_source_type":"vidburdir","_phd_member_id":474,"footnotes":""},"phd_school":[101,93],"phd_discipline":[105],"class_list":["post-6089","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-raunvisindadeild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-edlisfraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6089","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6089\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1837"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6089"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6089"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6089"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}