We　report　the　first　results　of　functional　properties　of　nitrogenized　silver-permalloy　thin　films　deposited　on　polyethylene　terephthalic　ester　{PETE　(C10H8O4)(n)}　flexible　substrates　by　magnetron　sputtering.　These　new　soft　magnetic　thin　films　have　magnetization　that　is　comparable　to　pure　Ni81Fe19　permalloy　films.　Two　target　compositions　(Ni76Fe19Ag5　and　Ni72Fe18Ag10)　were　used　to　study　the　effect　of　compositional　variation　and　sputtering　parameters,　including　nitrogen　flow　rate　on　the　phase　evolution　and　surface　properties.　Aggregate　flow　rate　and　total　pressure　of　Ar+N-2　mixture　was　60　sccm　and　0.55　Pa,　respectively.　The　distance　between　target　and　the　substrate　was　kept　at　100　mm,　while　using　sputtering　power　from　100-130　W.　Average　film　deposition　rate　was　confirmed　at　around　2.05　nm/min　for　argon　atmosphere　and　was　reduced　to　1.8　nm/min　in　reactive　nitrogen　atmosphere.　X-ray　diffraction,　X-ray　photoelectron　spectroscopy,　scanning　electron　microscopy,　vibrating　sample　magnetometer,　and　contact　angle　measurements　were　used　to　characterize　the　functional　properties.　Nano　sized　character　of　films　was　confirmed　by　XRD　and　SEM.　It　is　found　that　the　grain　size　was　reduced　by　the　formation　of　nitride　phase,　which　in　turns　enhanced　the　magnetization　and　lowers　the　coercivity.　Magnetic　field　coupling　efficiency　limit　was　determined　from　1.6-2　GHz　frequency　limit.　The　results　of　comparable　magnetic　performance,　lowest　magnetic　loss,　and　highest　surface　free　energy,　confirming　that　15　sccm　nitrogen　flow　rate　at　115　W　is　optimal　for　producing　Ag-doped　permalloy　flexible　thin　films　having　excellent　magnetic　field　coupling　efficiency.