modify icon size using iconCreateFunction in leaflet for R

Question

Using the quakes data as an example and the code below, I wish to modify the icon size. I need to keep the rest of the code as unchanged as possible, I just want to make the icons smaller. Can anyone please help?

library(leaflet)
data(quakes)
quakes<-head(quakes,10)
quakes$stations<-as.factor(quakes$stations)
map<-leaflet()
map<-addTiles(map,group = "OSM (default)")
map<-addMarkers(map,quakes$lon, quakes$lat, group = quakes$stations,
    clusterOptions = markerClusterOptions(maxClusterRadius = 5,transparent=TRUE,singleMarkerMode=TRUE,zoomToBoundsOnClick=FALSE,
        iconCreateFunction=JS(paste0("function(cluster) {
            var c = ' marker-cluster-small';
            var html = '<div style=\"background-color:rgba(","#FF00DB",")\"><span>' + cluster.getChildCount() + '</div><span>'
            return new L.DivIcon({html: html, className: 'marker-cluster' + c,iconSize: new L.Point(40, 40) });
        }"))
    )
)   

map