id sid tid token lemma pos b2773t9684b 1 1 the the DET b2773t9684b 1 2 study study NOUN b2773t9684b 1 3 of of ADP b2773t9684b 1 4 ferromagnetic ferromagnetic ADJ b2773t9684b 1 5 semiconductors semiconductor NOUN b2773t9684b 1 6 ( ( PUNCT b2773t9684b 1 7 fms fms PROPN b2773t9684b 1 8 ) ) PUNCT b2773t9684b 1 9 continues continue VERB b2773t9684b 1 10 to to PART b2773t9684b 1 11 be be AUX b2773t9684b 1 12 of of ADP b2773t9684b 1 13 great great ADJ b2773t9684b 1 14 interest interest NOUN b2773t9684b 1 15 because because SCONJ b2773t9684b 1 16 of of ADP b2773t9684b 1 17 their their PRON b2773t9684b 1 18 potential potential NOUN b2773t9684b 1 19 for for ADP b2773t9684b 1 20 spintronic spintronic ADJ b2773t9684b 1 21 devices device NOUN b2773t9684b 1 22 . . PUNCT b2773t9684b 2 1 while while SCONJ b2773t9684b 2 2 there there PRON b2773t9684b 2 3 has have AUX b2773t9684b 2 4 been be AUX b2773t9684b 2 5 much much ADJ b2773t9684b 2 6 progress progress NOUN b2773t9684b 2 7 in in ADP b2773t9684b 2 8 our our PRON b2773t9684b 2 9 understanding understanding NOUN b2773t9684b 2 10 of of ADP b2773t9684b 2 11 fms fms PROPN b2773t9684b 2 12 materials material NOUN b2773t9684b 2 13 & & CCONJ b2773t9684b 2 14 ndash ndash PROPN b2773t9684b 2 15 ; ; PUNCT b2773t9684b 2 16 particularly particularly ADV b2773t9684b 2 17 of of ADP b2773t9684b 2 18 the the DET b2773t9684b 2 19 canonical canonical ADJ b2773t9684b 2 20 iii iii NUM b2773t9684b 2 21 - - PUNCT b2773t9684b 2 22 v v NOUN b2773t9684b 2 23 system system NOUN b2773t9684b 2 24 gamnas gamnas PROPN b2773t9684b 2 25 & & CCONJ b2773t9684b 2 26 ndash ndash PROPN b2773t9684b 2 27 ; ; PUNCT b2773t9684b 2 28 many many ADJ b2773t9684b 2 29 issues issue NOUN b2773t9684b 2 30 still still ADV b2773t9684b 2 31 remain remain VERB b2773t9684b 2 32 unresolved unresolved ADJ b2773t9684b 2 33 . . PUNCT b2773t9684b 3 1 one one NUM b2773t9684b 3 2 of of ADP b2773t9684b 3 3 these these PRON b2773t9684b 3 4 is be AUX b2773t9684b 3 5 the the DET b2773t9684b 3 6 nature nature NOUN b2773t9684b 3 7 of of ADP b2773t9684b 3 8 interlayer interlayer NOUN b2773t9684b 3 9 exchange exchange NOUN b2773t9684b 3 10 coupling coupling NOUN b2773t9684b 3 11 ( ( PUNCT b2773t9684b 3 12 iec iec ADV b2773t9684b 3 13 ) ) PUNCT b2773t9684b 3 14 in in ADP b2773t9684b 3 15 gamnas gamnas PROPN b2773t9684b 3 16 - - PUNCT b2773t9684b 3 17 based base VERB b2773t9684b 3 18 multilayers multilayer NOUN b2773t9684b 3 19 , , PUNCT b2773t9684b 3 20 an an DET b2773t9684b 3 21 issue issue NOUN b2773t9684b 3 22 that that PRON b2773t9684b 3 23 is be AUX b2773t9684b 3 24 important important ADJ b2773t9684b 3 25 from from ADP b2773t9684b 3 26 the the DET b2773t9684b 3 27 point point NOUN b2773t9684b 3 28 of of ADP b2773t9684b 3 29 view view NOUN b2773t9684b 3 30 of of ADP b2773t9684b 3 31 possible possible ADJ b2773t9684b 3 32 spintronic spintronic ADJ b2773t9684b 3 33 applications application NOUN b2773t9684b 3 34 . . PUNCT b2773t9684b 4 1 in in ADP b2773t9684b 4 2 this this DET b2773t9684b 4 3 connection connection NOUN b2773t9684b 4 4 , , PUNCT b2773t9684b 4 5 it it PRON b2773t9684b 4 6 is be AUX b2773t9684b 4 7 important important ADJ b2773t9684b 4 8 to to PART b2773t9684b 4 9 establish establish VERB b2773t9684b 4 10 under under ADP b2773t9684b 4 11 what what DET b2773t9684b 4 12 conditions condition NOUN b2773t9684b 4 13 the the DET b2773t9684b 4 14 iec iec NOUN b2773t9684b 4 15 between between ADP b2773t9684b 4 16 successive successive ADJ b2773t9684b 4 17 gamnas gamna NOUN b2773t9684b 4 18 layers layer NOUN b2773t9684b 4 19 is be AUX b2773t9684b 4 20 antiferromagnetic antiferromagnetic ADJ b2773t9684b 4 21 ( ( PUNCT b2773t9684b 4 22 afm afm X b2773t9684b 4 23 ) ) PUNCT b2773t9684b 4 24 or or CCONJ b2773t9684b 4 25 ferromagnetic ferromagnetic ADJ b2773t9684b 4 26 ( ( PUNCT b2773t9684b 4 27 fm fm PROPN b2773t9684b 4 28 ) ) PUNCT b2773t9684b 4 29 , , PUNCT b2773t9684b 4 30 since since SCONJ b2773t9684b 4 31 manipulation manipulation NOUN b2773t9684b 4 32 of of ADP b2773t9684b 4 33 such such ADJ b2773t9684b 4 34 iec iec NOUN b2773t9684b 4 35 can can AUX b2773t9684b 4 36 then then ADV b2773t9684b 4 37 be be AUX b2773t9684b 4 38 directly directly ADV b2773t9684b 4 39 applied apply VERB b2773t9684b 4 40 to to PART b2773t9684b 4 41 achieve achieve VERB b2773t9684b 4 42 giant giant ADJ b2773t9684b 4 43 magnetoresistance magnetoresistance NOUN b2773t9684b 4 44 ( ( PUNCT b2773t9684b 4 45 gmr gmr PROPN b2773t9684b 4 46 ) ) PUNCT b2773t9684b 4 47 and and CCONJ b2773t9684b 4 48 other other ADJ b2773t9684b 4 49 devices device NOUN b2773t9684b 4 50 based base VERB b2773t9684b 4 51 on on ADP b2773t9684b 4 52 this this DET b2773t9684b 4 53 material material NOUN b2773t9684b 4 54 . . PUNCT b2773t9684b 5 1 in in ADP b2773t9684b 5 2 this this DET b2773t9684b 5 3 thesis thesis NOUN b2773t9684b 5 4 i i PRON b2773t9684b 5 5 describe describe VERB b2773t9684b 5 6 magneto magneto PROPN b2773t9684b 5 7 - - PUNCT b2773t9684b 5 8 transport transport NOUN b2773t9684b 5 9 , , PUNCT b2773t9684b 5 10 magnetization magnetization NOUN b2773t9684b 5 11 , , PUNCT b2773t9684b 5 12 and and CCONJ b2773t9684b 5 13 neutron neutron NOUN b2773t9684b 5 14 reflectometry reflectometry NOUN b2773t9684b 5 15 experiments experiment NOUN b2773t9684b 5 16 applied apply VERB b2773t9684b 5 17 to to ADP b2773t9684b 5 18 gamnas gamnas PROPN b2773t9684b 5 19 - - PUNCT b2773t9684b 5 20 based base VERB b2773t9684b 5 21 tri tri ADJ b2773t9684b 5 22 - - ADJ b2773t9684b 5 23 layer layer ADJ b2773t9684b 5 24 structures structure NOUN b2773t9684b 5 25 , , PUNCT b2773t9684b 5 26 consisting consist VERB b2773t9684b 5 27 of of ADP b2773t9684b 5 28 gamnas gamna NOUN b2773t9684b 5 29 layers layer NOUN b2773t9684b 5 30 separated separate VERB b2773t9684b 5 31 by by ADP b2773t9684b 5 32 non non ADJ b2773t9684b 5 33 - - ADJ b2773t9684b 5 34 magnetic magnetic ADJ b2773t9684b 5 35 gaas gaas NOUN b2773t9684b 5 36 spacers spacer NOUN b2773t9684b 5 37 . . PUNCT b2773t9684b 6 1 these these DET b2773t9684b 6 2 measurements measurement NOUN b2773t9684b 6 3 serve serve VERB b2773t9684b 6 4 to to PART b2773t9684b 6 5 identify identify VERB b2773t9684b 6 6 conditions condition NOUN b2773t9684b 6 7 under under ADP b2773t9684b 6 8 which which PRON b2773t9684b 6 9 afm afm NOUN b2773t9684b 6 10 coupling coupling NOUN b2773t9684b 6 11 will will AUX b2773t9684b 6 12 occur occur VERB b2773t9684b 6 13 in in ADP b2773t9684b 6 14 such such ADJ b2773t9684b 6 15 gamnas gamna NOUN b2773t9684b 6 16 / / SYM b2773t9684b 6 17 gaas gaas PROPN b2773t9684b 6 18 multilayer multilayer PROPN b2773t9684b 6 19 systems system NOUN b2773t9684b 6 20 , , PUNCT b2773t9684b 6 21 thus thus ADV b2773t9684b 6 22 providing provide VERB b2773t9684b 6 23 us we PRON b2773t9684b 6 24 the the DET b2773t9684b 6 25 information information NOUN b2773t9684b 6 26 which which PRON b2773t9684b 6 27 can can AUX b2773t9684b 6 28 be be AUX b2773t9684b 6 29 used use VERB b2773t9684b 6 30 for for ADP b2773t9684b 6 31 manipulating manipulate VERB b2773t9684b 6 32 magnetization magnetization NOUN b2773t9684b 6 33 ( ( PUNCT b2773t9684b 6 34 and and CCONJ b2773t9684b 6 35 thus thus ADV b2773t9684b 6 36 gmr gmr PROPN b2773t9684b 6 37 ) ) PUNCT b2773t9684b 6 38 in in ADP b2773t9684b 6 39 structures structure NOUN b2773t9684b 6 40 based base VERB b2773t9684b 6 41 on on ADP b2773t9684b 6 42 the the DET b2773t9684b 6 43 ferromagnetic ferromagnetic ADJ b2773t9684b 6 44 semiconductor semiconductor NOUN b2773t9684b 6 45 gamnas gamna NOUN b2773t9684b 6 46 . . PUNCT b2773t9684b 7 1 in in ADP b2773t9684b 7 2 addition addition NOUN b2773t9684b 7 3 , , PUNCT b2773t9684b 7 4 i i PRON b2773t9684b 7 5 describe describe VERB b2773t9684b 7 6 results result NOUN b2773t9684b 7 7 regarding regard VERB b2773t9684b 7 8 vertically vertically ADV b2773t9684b 7 9 graded grade VERB b2773t9684b 7 10 magnetic magnetic ADJ b2773t9684b 7 11 anisotropy anisotropy NOUN b2773t9684b 7 12 in in ADP b2773t9684b 7 13 gamnas gamnas PROPN b2773t9684b 7 14 . . PUNCT b2773t9684b 8 1 controlled control VERB b2773t9684b 8 2 vertical vertical ADJ b2773t9684b 8 3 grading grading NOUN b2773t9684b 8 4 of of ADP b2773t9684b 8 5 magnetization magnetization NOUN b2773t9684b 8 6 of of ADP b2773t9684b 8 7 the the DET b2773t9684b 8 8 ferromagnetic ferromagnetic ADJ b2773t9684b 8 9 semiconductor semiconductor NOUN b2773t9684b 8 10 gamnas gamna NOUN b2773t9684b 8 11 represents represent VERB b2773t9684b 8 12 a a DET b2773t9684b 8 13 significant significant ADJ b2773t9684b 8 14 step step NOUN b2773t9684b 8 15 toward toward ADP b2773t9684b 8 16 optimizing optimize VERB b2773t9684b 8 17 its its PRON b2773t9684b 8 18 magnetic magnetic ADJ b2773t9684b 8 19 properties property NOUN b2773t9684b 8 20 for for ADP b2773t9684b 8 21 device device NOUN b2773t9684b 8 22 applications application NOUN b2773t9684b 8 23 . . PUNCT b2773t9684b 9 1 we we PRON b2773t9684b 9 2 show show VERB b2773t9684b 9 3 that that SCONJ b2773t9684b 9 4 vertical vertical ADJ b2773t9684b 9 5 magnetization magnetization NOUN b2773t9684b 9 6 gradients gradient NOUN b2773t9684b 9 7 in in ADP b2773t9684b 9 8 gamnas gamna NOUN b2773t9684b 9 9 layers layer NOUN b2773t9684b 9 10 can can AUX b2773t9684b 9 11 readily readily ADV b2773t9684b 9 12 be be AUX b2773t9684b 9 13 achieved achieve VERB b2773t9684b 9 14 by by ADP b2773t9684b 9 15 appropriate appropriate ADJ b2773t9684b 9 16 growth growth NOUN b2773t9684b 9 17 strategies strategy NOUN b2773t9684b 9 18 , , PUNCT b2773t9684b 9 19 although although SCONJ b2773t9684b 9 20 quantitative quantitative ADJ b2773t9684b 9 21 control control NOUN b2773t9684b 9 22 of of ADP b2773t9684b 9 23 such such ADJ b2773t9684b 9 24 grading grading NOUN b2773t9684b 9 25 is be AUX b2773t9684b 9 26 difficult difficult ADJ b2773t9684b 9 27 in in ADP b2773t9684b 9 28 the the DET b2773t9684b 9 29 growth growth NOUN b2773t9684b 9 30 of of ADP b2773t9684b 9 31 such such ADJ b2773t9684b 9 32 layers layer NOUN b2773t9684b 9 33 due due ADP b2773t9684b 9 34 to to ADP b2773t9684b 9 35 various various ADJ b2773t9684b 9 36 competing compete VERB b2773t9684b 9 37 effects effect NOUN b2773t9684b 9 38 , , PUNCT b2773t9684b 9 39 such such ADJ b2773t9684b 9 40 as as ADP b2773t9684b 9 41 mn mn PROPN b2773t9684b 9 42 diffusion diffusion NOUN b2773t9684b 9 43 , , PUNCT b2773t9684b 9 44 self self NOUN b2773t9684b 9 45 - - PUNCT b2773t9684b 9 46 annealing annealing NOUN b2773t9684b 9 47 , , PUNCT b2773t9684b 9 48 and and CCONJ b2773t9684b 9 49 diffusion diffusion NOUN b2773t9684b 9 50 of of ADP b2773t9684b 9 51 charge charge NOUN b2773t9684b 9 52 carriers carrier NOUN b2773t9684b 9 53 . . PUNCT b2773t9684b 10 1 furthermore furthermore ADV b2773t9684b 10 2 , , PUNCT b2773t9684b 10 3 there there PRON b2773t9684b 10 4 also also ADV b2773t9684b 10 5 are be AUX b2773t9684b 10 6 several several ADJ b2773t9684b 10 7 surface surface NOUN b2773t9684b 10 8 effects effect NOUN b2773t9684b 10 9 that that PRON b2773t9684b 10 10 can can AUX b2773t9684b 10 11 influence influence VERB b2773t9684b 10 12 the the DET b2773t9684b 10 13 magnetization magnetization NOUN b2773t9684b 10 14 profile profile NOUN b2773t9684b 10 15 , , PUNCT b2773t9684b 10 16 which which PRON b2773t9684b 10 17 should should AUX b2773t9684b 10 18 be be AUX b2773t9684b 10 19 considered consider VERB b2773t9684b 10 20 in in ADP b2773t9684b 10 21 designing design VERB b2773t9684b 10 22 and and CCONJ b2773t9684b 10 23 fabricating fabricate VERB b2773t9684b 10 24 graded grade VERB b2773t9684b 10 25 gamnas gamna NOUN b2773t9684b 10 26 specimens specimen NOUN b2773t9684b 10 27 . . PUNCT b2773t9684b 11 1 polarized polarize VERB b2773t9684b 11 2 neutron neutron NOUN b2773t9684b 11 3 reflectometry reflectometry NOUN b2773t9684b 11 4 provides provide VERB b2773t9684b 11 5 direct direct ADJ b2773t9684b 11 6 evidence evidence NOUN b2773t9684b 11 7 that that SCONJ b2773t9684b 11 8 vertical vertical ADJ b2773t9684b 11 9 grading grading NOUN b2773t9684b 11 10 of of ADP b2773t9684b 11 11 mn mn PROPN b2773t9684b 11 12 concentration concentration NOUN b2773t9684b 11 13 has have AUX b2773t9684b 11 14 been be AUX b2773t9684b 11 15 successfully successfully ADV b2773t9684b 11 16 achieved achieve VERB b2773t9684b 11 17 in in ADP b2773t9684b 11 18 our our PRON b2773t9684b 11 19 gamnas gamna NOUN b2773t9684b 11 20 samples sample NOUN b2773t9684b 11 21 , , PUNCT b2773t9684b 11 22 and and CCONJ b2773t9684b 11 23 that that SCONJ b2773t9684b 11 24 the the DET b2773t9684b 11 25 samples sample NOUN b2773t9684b 11 26 exhibit exhibit VERB b2773t9684b 11 27 magnetic magnetic ADJ b2773t9684b 11 28 ' ' PUNCT b2773t9684b 11 29 hardening hardening NOUN b2773t9684b 11 30 ' ' PUNCT b2773t9684b 11 31 near near ADP b2773t9684b 11 32 the the DET b2773t9684b 11 33 surface surface NOUN b2773t9684b 11 34 . . PUNCT b2773t9684b 12 1 finally finally ADV b2773t9684b 12 2 , , PUNCT b2773t9684b 12 3 i i PRON b2773t9684b 12 4 describe describe VERB b2773t9684b 12 5 results result NOUN b2773t9684b 12 6 from from ADP b2773t9684b 12 7 efforts effort NOUN b2773t9684b 12 8 to to PART b2773t9684b 12 9 carefully carefully ADV b2773t9684b 12 10 engineer engineer VERB b2773t9684b 12 11 the the DET b2773t9684b 12 12 hole hole NOUN b2773t9684b 12 13 concentration concentration NOUN b2773t9684b 12 14 in in ADP b2773t9684b 12 15 gamnas gamna NOUN b2773t9684b 12 16 both both CCONJ b2773t9684b 12 17 after after ADP b2773t9684b 12 18 and and CCONJ b2773t9684b 12 19 during during ADP b2773t9684b 12 20 growth growth NOUN b2773t9684b 12 21 . . PUNCT b2773t9684b 13 1 when when SCONJ b2773t9684b 13 2 ge ge PROPN b2773t9684b 13 3 is be AUX b2773t9684b 13 4 grown grow VERB b2773t9684b 13 5 on on ADP b2773t9684b 13 6 gamnas gamna NOUN b2773t9684b 13 7 , , PUNCT b2773t9684b 13 8 the the DET b2773t9684b 13 9 incorporation incorporation NOUN b2773t9684b 13 10 of of ADP b2773t9684b 13 11 mn mn PROPN b2773t9684b 13 12 has have AUX b2773t9684b 13 13 already already ADV b2773t9684b 13 14 been be AUX b2773t9684b 13 15 fixed fix VERB b2773t9684b 13 16 during during ADP b2773t9684b 13 17 its its PRON b2773t9684b 13 18 growth growth NOUN b2773t9684b 13 19 , , PUNCT b2773t9684b 13 20 but but CCONJ b2773t9684b 13 21 the the DET b2773t9684b 13 22 holes hole NOUN b2773t9684b 13 23 are be AUX b2773t9684b 13 24 drained drain VERB b2773t9684b 13 25 off off ADP b2773t9684b 13 26 into into ADP b2773t9684b 13 27 ge ge PROPN b2773t9684b 13 28 . . PUNCT b2773t9684b 14 1 squid squid NOUN b2773t9684b 14 2 measurements measurement NOUN b2773t9684b 14 3 show show VERB b2773t9684b 14 4 tc tc PROPN b2773t9684b 14 5 in in ADP b2773t9684b 14 6 gamnas gamnas PROPN b2773t9684b 14 7 drops drop VERB b2773t9684b 14 8 rapidly rapidly ADV b2773t9684b 14 9 when when SCONJ b2773t9684b 14 10 layers layer NOUN b2773t9684b 14 11 of of ADP b2773t9684b 14 12 ge ge PROPN b2773t9684b 14 13 are be AUX b2773t9684b 14 14 deposited deposit VERB b2773t9684b 14 15 over over ADP b2773t9684b 14 16 it it PRON b2773t9684b 14 17 , , PUNCT b2773t9684b 14 18 the the DET b2773t9684b 14 19 decrease decrease NOUN b2773t9684b 14 20 in in ADP b2773t9684b 14 21 tc tc NOUN b2773t9684b 14 22 scaling scaling NOUN b2773t9684b 14 23 roughly roughly ADV b2773t9684b 14 24 with with ADP b2773t9684b 14 25 the the DET b2773t9684b 14 26 thickness thickness NOUN b2773t9684b 14 27 of of ADP b2773t9684b 14 28 the the DET b2773t9684b 14 29 ge ge PROPN b2773t9684b 14 30 layers layer NOUN b2773t9684b 14 31 . . PUNCT b2773t9684b 15 1 based base VERB b2773t9684b 15 2 on on ADP b2773t9684b 15 3 our our PRON b2773t9684b 15 4 current current ADJ b2773t9684b 15 5 understanding understanding NOUN b2773t9684b 15 6 of of ADP b2773t9684b 15 7 impurity impurity NOUN b2773t9684b 15 8 band band NOUN b2773t9684b 15 9 behavior behavior NOUN b2773t9684b 15 10 in in ADP b2773t9684b 15 11 gamnas gamna NOUN b2773t9684b 15 12 , , PUNCT b2773t9684b 15 13 this this DET b2773t9684b 15 14 precision precision NOUN b2773t9684b 15 15 control control NOUN b2773t9684b 15 16 over over ADP b2773t9684b 15 17 hole hole NOUN b2773t9684b 15 18 concentration concentration NOUN b2773t9684b 15 19 may may AUX b2773t9684b 15 20 be be AUX b2773t9684b 15 21 important important ADJ b2773t9684b 15 22 for for ADP b2773t9684b 15 23 efforts effort NOUN b2773t9684b 15 24 to to PART b2773t9684b 15 25 optimize optimize VERB b2773t9684b 15 26 tc tc PROPN b2773t9684b 15 27 . . PROPN b2773t9684b 16 1 in in ADP b2773t9684b 16 2 addition addition NOUN b2773t9684b 16 3 , , PUNCT b2773t9684b 16 4 i i PRON b2773t9684b 16 5 describe describe VERB b2773t9684b 16 6 efforts effort NOUN b2773t9684b 16 7 ( ( PUNCT b2773t9684b 16 8 and and CCONJ b2773t9684b 16 9 their their PRON b2773t9684b 16 10 unintended unintended ADJ b2773t9684b 16 11 consequences consequence NOUN b2773t9684b 16 12 on on ADP b2773t9684b 16 13 magnetic magnetic ADJ b2773t9684b 16 14 anisotropy anisotropy NOUN b2773t9684b 16 15 ) ) PUNCT b2773t9684b 16 16 to to PART b2773t9684b 16 17 control control VERB b2773t9684b 16 18 the the DET b2773t9684b 16 19 incorporation incorporation NOUN b2773t9684b 16 20 of of ADP b2773t9684b 16 21 mn mn NOUN b2773t9684b 16 22 in in ADP b2773t9684b 16 23 substitutional substitutional ADJ b2773t9684b 16 24 and and CCONJ b2773t9684b 16 25 interstitial interstitial ADJ b2773t9684b 16 26 positions position NOUN b2773t9684b 16 27 of of ADP b2773t9684b 16 28 gaas gaas NOUN b2773t9684b 16 29 via via ADP b2773t9684b 16 30 increasing increase VERB b2773t9684b 16 31 the the DET b2773t9684b 16 32 fermi fermi ADJ b2773t9684b 16 33 level level NOUN b2773t9684b 16 34 of of ADP b2773t9684b 16 35 gamnas gamna NOUN b2773t9684b 16 36 during during ADP b2773t9684b 16 37 the the DET b2773t9684b 16 38 growth growth NOUN b2773t9684b 16 39 by by ADP b2773t9684b 16 40 growing grow VERB b2773t9684b 16 41 gamnas gamna NOUN b2773t9684b 16 42 over over ADP b2773t9684b 16 43 ge ge PROPN b2773t9684b 16 44 layers layer NOUN b2773t9684b 16 45 . . PUNCT