000			03036ntm a2200349 i 4500
003			MY-KuUP
005			20260413120557.0
006			t||||fr|||| 000 0
007			ta
008			260413t20252025my a|||fr|||| 000 0 eng d
020			_aTHE0010451 (Local) _qHardback
040			_aUMPSA _beng _cUMPSA _erda
090			_aFIST .S56 2025 r Bc.
100	1		_aWong Sing Yee, _eauthor.
245	1	0	_aInfluence of particle size variations on electromagnetic absorption performance in bacomn hexaferrites/carbon hybrid composites / _cWong Sing Yee
264		1	_aKuantan, Pahang : _bUMPSA, _c2025
264		4	_c© 2025
300			_axvii, 95 pages : _billustrations ;
336			_2rdacontent _atext
337			_2rdamedia _aunmediated
338			_2rdacarrier _avolume
347			_2rda _atext file _bPDF
500			_aFaculty of Industrial Sciences and Technology
502			_aFinal Year Report (Bachelor of Applied Science in Material Technology) -- Universiti Malaysia Pahang Al-Sultan Abdullah - 2025
504			_aInclude bibliographical reference
520	3		_aMicrowave-absorbing materials are essential for radar stealth in military security and mitigating electromagnetic wave (EM) pollution caused by the widespread use of telecommunication devices. However, insufficient synergy between magnetic and dielectric losses and impedance mismatching constrain the absorption performance. This research was devoted to investigate the effect of particle size on the EM wave absorption properties of BaCoMn-hexaferrites (BCMFO) and BCMFO/activated carbon (AC) hybrid composites. The study aimed to enhance absorption by hybridizing high magnetic and dielectric losses of BCMFO and AC in a multilayer structure to minimize impedance mismatching. BCMFO was synthesized via the ball-milling with different milling times of 4, 8 and 12 hours to achieve varying particle sizes. Their effect on structural, microstructural and magnetic properties were analyzed, while electromagnetic absorption performance of BCMFO/AC with different thicknesses was measured in X-band frequency ranges. The smallest particle size of 0.20 μm, obtained after 4 h milling, demonstrated the lowest Ms, highest permeability, magnetic loss and negative RL. Conversely, the largest particle size of 0.30 μm from 12 h milling exhibited the lowest Hc, highest permittivity, and dielectric loss. Among the samples, the 1AC/1BCMFO(4) composite with a total thickness of 2 mm achieved the best absorption performance, attaining the highest negative RL of –16.66 dB and 90% absorption (< –10 dB) over a bandwidth of 1.86 GHz. The superior performance is attributed to improved impedance matching between magnetic and dielectric losses, enhanced interface polarization and hybridization of carbon.
610	2	0	_aFaculty of Industrial Sciences and Technology _xDissertations
650		0	_aUniversities and colleges _xDissertations
650		0	_aTheses _xDissertations
856			_uhttps://umpir.ump.edu.my/id/eprint/45997
942			_2lcc _cTHESIS
999			_c104726 _d104732